🆘 Disaster Lifeline — 災害ライフライン
The app you travel with should also be the app that protects you.
Japan lives with earthquakes, typhoons, and tsunami the way other countries live with weather. For a visitor, the hardest moment of a disaster is not the shaking — it is the minute after, standing in an unfamiliar city, reading warnings in a language you cannot parse, on a phone that may have just lost its network. The Matsuri iOS app ships a full 災害ライフライン (saigai lifeline, "disaster lifeline") for exactly that minute: 決済アプリが、もしもの時のライフラインになる — the payments app becomes a lifeline when it matters.
Every tool below is built on two hard rules: it must work fully offline, and it must work for guests with no login. A lifeline that requires a signal or a signup is not a lifeline.
🚨 Auto-activation: the app decides before you do
You should not have to remember which app has the disaster features while the ground is moving. A background service called DisasterWatchdog polls the public feeds of the JMA (Japan Meteorological Agency) every time the app launches or returns to the foreground. When a major event is detected, the app auto-presents a full-screen Disaster Hub — no menu diving, no search.
- Watchdog checks JMA public feedsOn every launch and foreground, DisasterWatchdog quietly polls JMA's public warning feeds.
- A major event is detectedThe feeds carry official warnings plus earthquake and tsunami reports; a major event trips the watchdog.
- The Disaster Hub takes the screenA full-screen lifeline hub appears automatically — for logged-in users and guests alike, online or offline.
Inside the hub, an official alerts view lists current JMA warnings plus recent earthquake and tsunami events, so you can see at a glance what is actually happening — not what social media thinks is happening.
🧰 Six lifeline tools
A nationwide evacuation-shelter dataset is bundled inside the app — map view plus a distance-sorted list, with zero network required. The moment you need a shelter is the moment the network is least reliable.
A great-circle bearing compass that simply points at the nearest shelter. When streets are blocked and map tiles will not load, an arrow and a distance are enough.
Offline per-hazard DO/DON'T cards in 5 languages, plus Japan's emergency phone numbers. What to do, and what not to do, for each kind of disaster — in words you actually read.
Turns the torch or the screen into a Morse SOS beacon (··· ––– ···) — a century-old signal every rescuer recognizes, produced by the device already in your hand.
An offline peer-to-peer mesh bulletin board: phones relay signed messages hop-to-hop to nearby devices, with multi-hop relay carrying posts beyond direct radio range. Communication that survives the death of the cell network.
Report "I'm safe" through whichever channel still works: the mesh, SMS, the iOS share sheet, or web171 — Japan's official disaster message board service.
Most disaster apps are thin clients over an API — useful right up until the moment they are needed. Matsuri ships the shelter dataset, the safety guides, and the compass logic inside the app binary. Airplane mode is a valid test: switch it on and every tool above still works.
📡 The mesh: a network made of phones
The most fragile assumption in any emergency plan is "the network will be up." Matsuri's mesh bulletin board drops that assumption entirely. Each phone talks directly to nearby phones, and every phone relays what it hears, so a message hops device-to-device across a neighborhood with no tower, no router, and no internet anywhere in the chain. Messages are signed, so a relayed post still provably comes from its original author.
The same mesh doubles as a delivery rail for the safety check-in — your "I'm safe" can travel out of a blackout zone by riding other people's phones until it reaches one with a working connection.
- Transport
- Peer-to-peer phone mesh — no cell network, no Wi-Fi infrastructure, no server
- Reach
- Multi-hop relay — messages travel beyond direct radio range
- Trust
- Messages are signed, so relayed posts remain attributable
- Check-in rails
- Mesh / SMS / share sheet / web171
🤝 Rebuild together
A lifeline gets you through the first hours. What happens to a community in the months after is where the rest of the Matsuri economy takes over.
The Crowdfunding engine supports disaster-recovery (災害復興) campaigns at boosted MTC cashback: the standard cashback is 1% of a contribution multiplied by your GCF tier, and special campaigns can be approved at a per-campaign multiplier of up to 3.0×. The community that the platform protects during a disaster is the same community it mobilizes to rebuild afterward.
The flagship example is the Noto Peninsula earthquake relief effort — funding the recovery of 輪島塗 (Wajima-nuri, Wajima lacquerware) workshops, so that a centuries-old craft damaged in minutes is not lost for good. Backers are rewarded in MTC for helping a craft survive; the craft, once revived, returns to the platform as bookable experiences and shop inventory. Protection and regeneration run on one loop.
Nothing about the lifeline requires ever touching the token — it is free, offline, and login-free. But the fact that it lives in the same app as crowdfunding and the MTC economy is the point: the tool that helps you find a shelter on Tuesday is the tool that helps rebuild the town on Saturday.
What this is — and what it is not
- The Disaster Lifeline is a feature of the Matsuri iOS consumer app — see Product & Tech for the app portfolio.
- Alert data comes from JMA public feeds. Matsuri has no affiliation with the JMA or any government agency, and this is not a government service.
- These tools are a supplement, not a substitute for official guidance. In an emergency, always follow the instructions of local authorities and official evacuation orders.
Most of this whitepaper describes what Matsuri does on a good day: experiences, dining, shopping, earning. This chapter is about the bad day — and the belief that an app asking for a place in a traveler's pocket owes them something when the ground shakes. 温故知新 (onko-chishin, "learn from the old to build the new") applies here too: shelter maps, Morse code, and neighbor-to-neighbor message relay are old ideas — Matsuri just makes sure they are already on your phone.