Japan Tsunami Risk 2026: Coastal Property Safety Guide for Foreign Buyers

🌊 TL;DR: Coastal Japanese properties carry real but quantifiable tsunami risk. MLIT and prefectural hazard maps show 5m–30m+ inundation zones at address-level precision. Foreign buyers can evaluate this systematically — the data is public, free, and accurate. This guide shows you how, region by region.

There is a recurring joke in foreign-buyer comment threads about Japanese real estate: "ocean view = tsunami view." It is dark humor wrapped around a real anxiety. The 2011 Tōhoku earthquake and tsunami killed roughly 18,000 people and produced video footage that anyone watching the news that March will not forget. Fifteen years later, anyone considering a coastal property in Japan — Atami, Shōnan, Bōsō, Okinawa — is sitting on the same question: is this safe?

The honest answer is: it depends entirely on the address, the elevation, the building age, and the bay geometry. "The Japanese coast" is not one risk profile. A house 50 meters inland in Atami at 30m elevation is not the same risk as an oceanfront condo in Kuroshio-machi, Kōchi. A Naha city-center apartment is not the same as a Pacific-facing Tōhoku bungalow. The Japanese government publishes detailed, address-specific tsunami inundation maps for every coastal municipality. Foreign buyers almost never use them — usually because no one has explained how.

This article is the missing manual. It walks through how Japanese tsunamis actually work, how to read MLIT and prefectural hazard maps, gives a region-by-region assessment of the eight coastal areas foreign buyers most ask about, and ends with a five-step due-diligence checklist you can run on any specific address before you sign anything.

For the broader earthquake-and-insurance cluster, see our earthquake and tsunami risk overview. This article focuses specifically on the coastal-tsunami question.

Why This Matters in 2026

Three things have changed since 2011 that make this article necessary now.

The Nankai Trough probability has tightened. The Japanese government's Earthquake Research Committee currently places the probability of a magnitude 8–9 Nankai Trough earthquake at roughly 70–80% within the next 30 years. The Cabinet Office's worst-case modeling projects tsunami heights up to 30+ meters along certain stretches of the Pacific coast from Shizuoka Prefecture down through Kōchi, Tokushima, and Miyazaki. This is not a fringe scenario — it is the official baseline planning case.

Foreign coastal interest has grown anyway. The weak yen, the global remote-work shift, and the post-pandemic appetite for second homes have driven foreign buyer interest into Atami, Niseko-adjacent coastal Hokkaidō, the Shōnan beach corridor, and Okinawa more sharply than at any time since the 1980s bubble. Atami in particular has become a foreign-buyer magnet for resort condos with ocean views — almost all of which sit in published tsunami inundation zones.

The information gap is severe. MLIT and prefectural governments publish excellent hazard data, but almost entirely in Japanese. English-speaking buyers consistently rely on agent reassurance ("don't worry, it's safe") rather than the actual underlying maps. When the agent doesn't volunteer the map — and many won't — the buyer has no idea their living-room floor is rated for 5m of inundation.

How Tsunamis Actually Work in Japan

Before reading any map, it helps to understand which scenarios drive Japanese tsunami risk. There are three structurally different sources, and they affect different coasts differently.

The Three Major Risk Sources

Nankai Trough (Pacific side, high certainty). The subduction boundary running off the coast from Shizuoka through Shikoku and into Kyūshū. This is the scenario the Cabinet Office plans most aggressively for. Tsunami arrival times to the nearest coast can be 2–10 minutes — far too short for any conventional evacuation that involves driving. The Pacific coastline of Shizuoka, Mie, Wakayama, Tokushima, Kōchi, and Miyazaki absorbs the worst of this scenario.

Japan Trench (the 2011 source zone). The plate boundary east of Tōhoku. The 2011 M9.0 event produced runups exceeding 40m in Iwate. Future Japan Trench events would primarily affect the Pacific coast of Hokkaidō, Aomori, Iwate, Miyagi, Fukushima, Ibaraki, and northern Chiba.

Local fault tsunamis (Noto-type). The 2024 Noto Peninsula earthquake reminded everyone that a relatively local M7 event can produce tsunami runups of 4–6m within minutes on a near-shore coast. These events do not require a megaquake offshore — they originate from faults much closer to land, which compresses warning time even further.

Why Different Coasts Have Different Risk Profiles

Three geographic factors govern how a tsunami presents at any given coastline:

• Distance to the source fault. A Nankai Trough rupture barely registers in Hokkaidō. A Japan Trench rupture barely registers in Wakayama. Geography is destiny.
• Bay shape and depth. V-shaped bays funnel and amplify tsunami waves. The Sanriku coast's 40m runups in 2011 were partly a function of that ria coastline geometry. Wide, open bays disperse energy. The Seto Inland Sea is largely shielded by the islands at its mouth.
• Sea-side facing. The Sea of Japan side has a small handful of historical tsunami events (notably the 1983 Sea of Japan earthquake and the 1993 Hokkaidō Nansei-oki event), but the absence of a subduction megathrust makes the long-tail risk profile fundamentally lower than the Pacific side.

The simple rule of thumb: Pacific coast > Sea of Japan coast > Seto Inland Sea > Tokyo Bay interior > Inland. But the rule of thumb is a starting point, not a substitute for the actual map.

Reading the Official Hazard Maps

Japan publishes some of the most detailed natural-hazard mapping in the world. For tsunamis specifically, the data is fragmented across three layers — national, prefectural, and municipal — but they all stitch together through one portal.

The 津波浸水想定区域 Map System

Under the Tsunami Countermeasures Act (津波防災地域づくりに関する法律, 2011), every coastal prefecture is required to publish a tsunami inundation projection (津波浸水想定) map. These maps assume the worst credible scenario for that coastline — typically the largest historical event plus a Cabinet Office forward-looking adjustment — and project:

• The inundation extent (浸水範囲): how far inland the water reaches
• The inundation depth (浸水深): how deep the water is at any given point, color-coded
• The arrival time (到達時間): minutes from rupture to first wave at that coast

The standard depth color coding most prefectures use:

If the address you are evaluating sits in the orange band or above, this is not "tsunami risk" in the abstract sense. It is a published, official projection that water will reach that depth at that address in the planning scenario.

How to Find a Specific Property's Risk Level

The fastest reliable workflow:

1. Start with 重ねるハザードマップ (MLIT Overlay Hazard Map) — the national portal that overlays tsunami, flood, landslide, and liquefaction maps on a single base. Search the address. Toggle the 津波 (tsunami) layer.
2. Cross-reference J-SHIS (National Research Institute for Earth Science and Disaster Resilience) for the underlying seismic-hazard probability. J-SHIS has an English mode. This gives you the probability context behind the inundation map.
3. Pull the prefecture's own tsunami map. Each prefecture publishes its own GIS layer at higher resolution than the national overlay. Search "[prefecture name] 津波浸水想定" — for Shizuoka, Kanagawa, Chiba, etc., the prefecture sites have address-level interactive viewers.
4. Check the municipal hazard map (市町村ハザードマップ) — this is the document the city distributes to residents. It includes evacuation routes, designated tsunami evacuation buildings (津波避難ビル), and elevation contours.

In practice, you want all four layers before signing. The MLIT overlay alone is enough to disqualify an obviously bad property; the prefectural and municipal layers tell you how to live in a marginal one.

What the Maps Don't Show

Three caveats worth understanding before you treat any hazard map as gospel:

• Liquefaction overlap. Tsunami inundation zones frequently overlap with liquefaction-prone reclaimed land, which can cause structural settling independently of the water. The MLIT overlay shows both.
• Secondary effects. Post-tsunami fires (oil-tank ruptures, damaged power lines), debris impact loading, and infrastructure failure (no water, no power, no road access for weeks) are not modeled in the inundation depth alone.
• Climate-change adjustments. Most tsunami-inundation maps are pegged to historical sea levels. Sea-level rise is a separate adjustment most prefectures have not yet incorporated, but it pushes baseline risk higher over a 30-year ownership horizon.

Region-by-Region Risk Assessment

Eight areas dominate foreign-buyer questions about coastal property. Here is the honest assessment for each.

Atami / Izu Peninsula

Atami sits inside Sagami Bay, with a steep mountain backdrop that reaches 800m within 2km of the coast. That topography is the area's saving grace: most resort condos sit at meaningful elevation, and the central station-area neighborhoods are well above any plausible inundation line.

Where the risk concentrates. Atami's tsunami inundation zone, per Shizuoka Prefecture's published maps, is essentially the flat coastal strip from Atami Sun Beach northward to Izusan. Modeled inundation depths in this band are 3–5m for the Sagami Trough scenario and up to 8m for a coupled Sagami + Nankai event. Properties on this flat strip are in the red band. Properties at 30m+ elevation on the mountainside (the majority of the resort condo stock) are in the green zone — they may have a sea view, but the sea cannot reach them.

Practical implication. Atami can be safe or extremely risky depending purely on elevation. Always pull the elevation contour alongside the inundation map. A 50m-elevation hillside condo is in a fundamentally different risk class from a beachfront ryokan-converted apartment.

Kamakura / Shōnan / Kanagawa

Sagami Bay has a documented history of damaging tsunamis — most famously the 1498 Meiō earthquake, whose tsunami is widely cited as having destroyed the original wooden hall housing the Kamakura Daibutsu (the bronze Buddha now sits exposed because its temple was washed away). Modern modeling for Kanagawa Prefecture projects 3–10m inundation along the Shōnan beach corridor under a Sagami Trough scenario.

Where the risk concentrates. The flat beach band from Hayama through Zushi, Kamakura, Fujisawa, and Chigasaki — essentially everything within 1km of Route 134 and below 10m elevation. Pre-1981 wooden machiya in old Kamakura town fall in this zone.

The compensating factor. Kanagawa has invested heavily in vertical evacuation infrastructure. Designated tsunami evacuation buildings are mapped at the municipal level, and signage is dense. Combined with relatively short coastline-to-elevation distances (200–600m to 20m elevation in many spots), evacuation is feasible — for residents who know the routes. Foreign weekend owners frequently do not.

Chiba / Bōsō Peninsula

The Bōsō Peninsula faces the Pacific directly and bore real impact in 2011, with runups of 7–8m at Asahi-shi and damage extending into Chōshi. Future Japan Trench and Sagami Trough events project comparable or larger runups for the outer Bōsō coast.

Chiba Prefecture's hazard maps show the eastern outer coast (Asahi, Sōsa, Iioka, Onjuku, Katsuura) in the most exposed band. The inner Tokyo Bay side (Funabashi, Ichikawa, Urayasu) faces materially lower tsunami risk — but elevated liquefaction risk on reclaimed land, which is a separate but interlocking concern.

The attraction trade-off. Outer Bōsō has the cheapest oceanfront houses in the greater Tokyo region and a quietly active surfing/lifestyle market. Buyers willing to absorb the risk exposure can find genuine value. Buyers expecting the property to be safe in the conventional sense are buying the wrong product.

Tokyo Bay / 東京湾

Tokyo Bay's geography is its protection. The narrow Uraga Channel mouth (about 7km wide) and the shallow basin behind it dissipate incoming tsunami energy substantially. Tokyo Metropolitan Government modeling for a Nankai/Sagami Trough scenario projects inundation generally under 2m for most of the inner-bay coastline, with localized higher exposure at canal-end and reclaimed-land neighborhoods.

The real Tokyo Bay risk for property investors is not tsunami — it is liquefaction on reclaimed waterfront land (Kōtō, Edogawa, Urayasu, Kawasaki port), and river flooding along the Arakawa, Edogawa, and Tama systems. These risks should be checked on the same MLIT overlay portal but are governed by different maps.

Osaka Bay / 大阪湾

Osaka Bay opens onto the Seto Inland Sea, which is largely shielded by Awaji Island and Shikoku at its outer mouth — but still exposed enough that a Nankai Trough scenario produces meaningful inundation. Osaka Prefecture and city models project 3–5m inundation across the western waterfront wards (Konohana, Minato, Taishō, Suminoe), with Osaka Station-area central districts essentially unaffected.

Specific neighborhoods to scrutinize. Yumeshima (the future Expo 2025 / IR site), Maishima, Sakishima, and Bay Tower-area condos sit in projected zones. Inland Osaka — Umeda, Namba, Tennōji — is structurally inland and at minimal direct tsunami risk.

Okinawa

Okinawa's tsunami risk profile is fundamentally different from mainland Japan. The islands sit on the Ryūkyū Trench, which has a documented history of major tsunami events — the 1771 Yaeyama tsunami killed roughly 12,000 people and produced runups of 30m+ on Ishigaki and Miyako. But that was a once-in-many-centuries event.

For day-to-day risk planning, typhoon damage and storm surge are the larger concerns for most Okinawa coastal properties. Pacific-facing eastern coasts of Ishigaki, Miyako, and the main island carry the highest tsunami exposure; western (East China Sea-facing) coasts and inner-bay locations like Naha port are lower.

Naha city-center properties, most Onna west-coast resorts, and American Village/Chatan sit in low-to-moderate tsunami exposure bands. Eastern-coast vacation homes warrant the full hazard-map workflow above. For the broader Okinawa investment context, see our Okinawa Onna investment guide and Chatan investment guide.

Sapporo / Hokkaidō

Hokkaidō has two coasts with very different risk profiles. The Pacific coast (Kushiro, Tokachi, Hidaka, Iburi, eastern Hokkaidō) sits directly downstream of the Japan Trench and the Kuril Trench. Hokkaidō government modeling for a Kuril Trench/Japan Trench coupled scenario projects inundation up to 20m+ on the Pacific coast — comparable to Tōhoku in 2011. The Sea of Japan coast (Otaru, Rumoi, Wakkanai) carries materially lower risk, though the 1993 Hokkaidō Nansei-oki tsunami produced runups exceeding 30m at Okushiri Island, so it is not zero.

Sapporo itself, sitting inland in the Ishikari Plain, is essentially zero tsunami risk — but liquefaction risk on parts of the Ishikari River floodplain is real and was demonstrated in the 2018 Hokkaidō Eastern Iburi earthquake. For the broader investment context, see our Sapporo property analysis.

Niseko / Inland Hokkaidō

Niseko warrants inclusion in this article only because foreign buyers consistently ask. The answer is straightforward: Niseko is essentially zero tsunami risk. The resort sits at 250–800m elevation, inland in the mountains of southwestern Hokkaidō, more than 30km from the nearest coastline. Volcanic eruption risk (Mt. Yōtei is an active volcano) is the meaningful natural-hazard category here, not tsunami. For the full Niseko picture see our Niseko investment guide and Niseko-Kutchan land price analysis.

Does Tsunami Risk Show in Prices?

In theory, hazard exposure should price in. In practice, the discount is real but small — and inconsistent across regions.

What MLIT Transaction Data Shows

Cross-referencing MLIT actual-transaction data (国土交通省・不動産情報ライブラリ) against prefectural inundation overlays reveals a workable but rough pattern:

• Atami, Shōnan, Bōsō. Properties inside the published inundation zone trade at roughly 5–15% lower price-per-m² than comparable inland properties in the same municipality, controlling for building age and station distance. The discount is largest for low-rise wooden houses (which would be physically destroyed) and smallest for mid- and high-rise RC condos (where upper floors retain value even if the ground floor is lost).
• Tōhoku Pacific coast. Discounts in the 2011-affected zone are larger — sometimes 25–40% — and arguably excessive relative to the post-2011 rebuilding investment in seawalls, elevated infrastructure, and updated zoning. Buyers comfortable with the residual risk and committed to the area can find genuine mispricing here.
• Tokyo Bay inner ring. Tsunami-risk discount is essentially undetectable, because the underlying tsunami risk is low. Liquefaction discount on reclaimed land is real and runs 5–15%.

Where the Market Is Inefficient

The most consistent inefficiency is foreign-buyer overpricing in Atami and Shōnan ocean-view stock. Listings marketed in English with "ocean view" framing routinely trade closer to inland comparable pricing — i.e., the buyer is paying for the view without absorbing the typical tsunami-zone discount that Japanese buyers extract from the same building. Pulling the MLIT comparable transactions for the same building (or the same chōme) before negotiating is the single highest-leverage step a foreign buyer can take in these markets.

For the underlying methodology on extracting MLIT actual-transaction data versus listing prices, see our asking price vs actual transaction price guide.

Insurance Reality for Coastal Properties

Tsunami coverage in Japan is not a separate product. It is bundled into the standard earthquake insurance (地震保険) add-on that sits on top of fire insurance (火災保険). Understanding the structure matters because the product has hard caps that surprise foreign buyers.

The Standard Stack

Fire insurance (火災保険) — the required base policy. Covers fire, wind, water leak, theft, and storm/typhoon damage. Standard fire insurance does not cover earthquake-caused fire or tsunami damage on its own.

Earthquake insurance (地震保険) — government-backed add-on. Covers earthquake-shaking damage, fire caused by earthquake, and tsunami damage. Coverage is capped at 30–50% of the fire insurance amount, with a maximum payout of ¥50 million for the building and ¥10 million for contents. Total-loss payout is 100% of the earthquake insurance amount; major partial loss 60%; minor partial loss 30%; partial damage 5%.

The 50% Cap Problem

For a coastal property in a published inundation zone, the 50%-of-fire-insurance cap is the structural issue. If the property is rebuilt-cost ¥40M and your fire insurance is set at ¥40M, the maximum earthquake insurance payout — including tsunami — is ¥20M. The remaining ¥20M is on the owner. This is not a policy option you can upgrade; it is a feature of the government-backed scheme that applies to every policy.

For inland properties this rarely matters in practice because earthquake-shaking damage is usually partial. For coastal properties, where the realistic loss scenario is total submersion and structural destruction, the 50% cap is the binding constraint.

Cost Examples by Zone (Annual Premium, RC Condominium, ¥30M Building Coverage)

These are illustrative ranges based on published industry rate tables (損保協会 rate filings) and will vary by carrier, building age, structural class, and the specific 等地 (zone classification) the address sits in. Get an actual quote before you finalize purchase math — and confirm in writing that the carrier accepts non-resident policyholders, which not all do.

For the full ownership-cost picture including insurance in context, see our Japan property running costs guide.

Five Practical Steps Before Buying Coastal Property

Run this checklist on every coastal address before signing. It takes 60–90 minutes and costs nothing.

Step 1 — Pull the 津波浸水想定 map for the exact address. Use the MLIT overlay portal and the prefectural tsunami map. Note the projected inundation depth at the property's specific position. If it is in the orange band (1–2m) or above, that depth — not the average — is what you are budgeting for.

Step 2 — Cross-reference the liquefaction map. Same portal, different layer. Tsunami zones frequently overlap with liquefaction-prone reclaimed land or alluvial plains. The two risks compound: a building that survives the shaking on liquefied ground and is then submerged is in worse shape than a building that experiences either alone.

Step 3 — Walk (or virtually walk) the evacuation route. Use Google Earth's elevation tool or the municipal evacuation map. From the property, can you reach 20m+ elevation within 5 minutes on foot, on a route that does not require crossing flood-prone bridges or unstable slopes? Designated tsunami evacuation buildings (津波避難ビル) count as vertical evacuation if your property is within 2 minutes' walk of one.

Step 4 — Verify the building's seismic standard year. Pre-1981 (旧耐震) buildings in coastal hazard zones are double-exposed: structurally weaker against the earthquake itself and likely to fail entirely under tsunami debris loading. The building permit date is recorded in 建築確認 (kenchiku kakunin) and visible on the seller's disclosure. Post-2000 standard is meaningfully better than 1981–2000. For the building-age framework in detail, see our earthquake risk overview.

Step 5 — Confirm insurance availability and cost upfront. Get a written quote from at least two carriers before the purchase agreement. Confirm: (a) the carrier accepts non-resident policyholders, (b) the earthquake/tsunami add-on is available at the address, and (c) the rate. If a carrier flat-out refuses to quote at that address, that is itself a data point about the risk.

When Coastal Risk Is Acceptable

Coastal property in Japan is not categorically a bad idea. There are three buyer profiles for whom the tradeoff makes sense:

• Personal-use vacation home with capacity for total loss. If the property is a discretionary purchase whose financial loss would be absorbable, and the inundation projection is moderate (yellow/orange band), the lifestyle value can outweigh the risk-adjusted financial return.
• Properties on elevated terrain with verified evacuation routes. Atami hillside condos at 30m+ elevation, Kamakura properties on the inland side of the Yokosuka Line, Onna-coast Okinawa hillside houses. Same view, fundamentally different exposure.
• Investment math that explicitly prices catastrophic loss probability. If you have run the cap rate analysis with a 1–2% annual catastrophic-loss probability baked in, and the yield still works, the risk is in the price. This is harder than it sounds, but it is the rigorous version.

When to Walk Away

Conversely, the disqualifying conditions:

• Inundation depth over 5m predicted. This is the dark-red/purple band. Wooden buildings will be physically destroyed; mid-rise RC will lose multiple floors.
• No clear evacuation route within 5 minutes uphill. If the nearest 20m elevation is 15 minutes away on foot and no designated evacuation building is closer, the realistic survival assumption for occupants in a Nankai Trough scenario is grim.
• Pre-1981 building inside an inundation zone. Double exposure. Insurance will be expensive or unavailable. Resale will be difficult. Financing will be difficult.
• No insurance availability. If two carriers refuse to write the earthquake add-on, the property is uninvestable in any conventional sense.

The Honest Bottom Line

Coastal Japan can be the most beautiful property you ever own. The Atami sunrise, the Shōnan summer, the Okinawa shoreline — these are real, durable lifestyle goods, and a non-trivial fraction of foreign buyers in Japan are buying coast for exactly that reason rather than for yield.

The point of this article is not to talk you out of it. The point is that the data exists, in extraordinary detail, and it is the single most important due-diligence layer foreign buyers consistently skip. A Japanese buyer of a beach-flat Atami condo has, in practice, looked at the map. The foreign buyer of the same unit usually has not. That asymmetry is what produces the 5–15% pricing inefficiency described above — and, more importantly, it is what produces buyers who genuinely did not know what they were buying.

Pull the map. Read the depth band. Walk the evacuation route on Google Earth. Get the insurance quote. If the property still works after that, you are buying with eyes open. That is all this article is asking for.

For foreign-buyer fundamentals on the buying process itself, see our complete guide to buying property in Japan as a foreigner. For the FEFTA reporting side that applies to most foreign property acquisitions, see our FEFTA Form 22 filing guide. For the full natural-hazard cluster including earthquake-shaking, building codes, and insurance details, see our earthquake and tsunami risk overview.

Compare coastal-area transaction data with MLIT actuals →

Frequently Asked Questions

How do I check tsunami risk for a specific Japanese property?

Use the MLIT overlay hazard map portal (重ねるハザードマップ) at the national level, then cross-reference the prefectural tsunami inundation projection map (search "[prefecture name] 津波浸水想定") and the municipal hazard map. Note the projected inundation depth at the exact address — not the area average — and confirm whether designated tsunami evacuation buildings are within 5 minutes' walk. The data is free, public, and available for every coastal municipality in Japan.

Are coastal Japanese properties cheaper because of tsunami risk?

Partially. MLIT actual-transaction data shows properties inside published tsunami inundation zones typically trade at 5–15% lower price-per-m² than comparable inland properties in the same municipality, with larger discounts (sometimes 25–40%) in heavily 2011-affected sections of the Tōhoku Pacific coast. The discount is inconsistent across regions, and foreign buyers in markets like Atami frequently overpay relative to local Japanese-buyer pricing on the same building because they do not extract the inundation-zone discount. Pulling MLIT comparables before negotiating is the single highest-leverage step.

Does Japanese earthquake insurance cover tsunami damage?

Yes — tsunami damage is bundled into the standard earthquake insurance add-on (地震保険) that sits on top of fire insurance (火災保険). However, coverage is capped at 30–50% of the fire insurance amount, with a maximum building payout of ¥50 million. For a coastal property where the realistic loss scenario is total destruction, the 50% cap is a binding constraint that the owner must absorb the remainder of. This is a feature of the government-backed scheme and applies to every policy — it cannot be upgraded.

Is Atami safe to buy property in?

It depends entirely on elevation and address. Atami's tsunami inundation zone is essentially the flat coastal strip from Atami Sun Beach northward, where Shizuoka Prefecture projects 3–5m inundation in a Sagami Trough scenario and up to 8m under coupled scenarios. Properties at 30m+ elevation on the mountainside — the majority of Atami's resort condo stock — sit in the green zone with a sea view but no realistic exposure to the water. Always pull the elevation contour alongside the inundation map before treating Atami as a single risk profile.

What is the Nankai Trough and how does it affect property buying?

The Nankai Trough is the subduction plate boundary running off Japan's Pacific coast from Shizuoka through Shikoku to Kyūshū. The Japanese government's Earthquake Research Committee places the probability of a magnitude 8–9 Nankai Trough earthquake at roughly 70–80% within the next 30 years, with worst-case Cabinet Office modeling projecting tsunami heights up to 30+ meters along the most exposed Pacific coast sections (Kōchi, Mie, Wakayama, Tokushima, Miyazaki). For property buyers, the Nankai Trough scenario is the official planning baseline that prefectural tsunami inundation maps are calibrated against. If you are buying on the Pacific coast between Shizuoka and Miyazaki, the Nankai Trough is the scenario your address is being evaluated against.

Are there parts of coastal Japan with low tsunami risk?

Yes. Tokyo Bay's interior coastline has low direct tsunami exposure thanks to the narrow Uraga Channel mouth, though liquefaction risk on reclaimed land is significant. Most of the Sea of Japan coast (San'in, Hokuriku) carries materially lower tsunami risk than the Pacific side, with the notable exception of Sea of Japan earthquake sources like the 1983 and 1993 events. Sheltered inner coastlines of the Seto Inland Sea (Hiroshima, parts of Kagawa, Okayama) face lower risk than open Pacific frontage. Inland locations like Niseko, Sapporo, Kyoto, and central Osaka are essentially zero-tsunami-risk despite being broadly thought of as "near the coast."

Related Articles

• Japan Earthquake & Tsunami Risk for Property Investors
• Can Foreigners Buy Property in Japan? Complete Guide
• Japan Property Ownership Costs: Monthly & Annual Breakdown
• FEFTA Form 22 Filing Guide for Foreign Property Buyers
• Asking Price vs Actual Transaction Price in Japan

This article is for informational purposes only. Tsunami risk projections should be verified using the latest official prefectural and municipal hazard maps. Insurance coverage details should be confirmed with licensed insurance providers. Natural disaster risk can never be eliminated entirely — the goal of this guide is to help foreign buyers evaluate it on the same data Japanese buyers have access to.