Lost Gaijin
A Japanese learning game
Learn Japanese by getting lost in it.
You step off a local train in the Shikoku countryside with ¥250,000, a paper address note, and almost no Japanese. It's 1 p.m. on a Sunday in 1994. No smartphones, no translation apps, no GPS. The attendant holds out one hand.
Attendant
「切符をお願いします。」 Ticket, please.
You
(your reply)
Everything you learn from here, you learn because you need it.
Windows, Mac & Linux at launch
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From Ten Turtle Games
- Get lost. Get fluent.
- The whole country is the classroom
The setup · May 8, 1994 · 1:00 p.m.
A world without a script
Lost Gaijin is a text adventure set in a persistent, AI-directed Japan. You type what you do, and the language you type it in grows: English first, broken Japanese soon, real Japanese eventually. Two AIs read every turn with you. The Storyteller writes the scene; the Coach grades your Japanese while the story keeps moving. Say anything, try anything: the world takes it seriously, and the story is whatever happens next.
This is the game's real view, running live. The attendant has asked for your ticket; the traveler submits their first words — one Japanese word, English, and a hopeful question mark — and gets 「はい、どうぞ。」 in return. See the graduation-cap badge pulsing on that message? Click it: that's the Coach, grading what you wrote and handing you the Japanese for next time. Click any word in the scene and the inspector dissects its reading, grammar, and conjugation. The reply bar is already holding your thanks, unsubmitted.
How it teaches
The study schedule hides under the story
There is no flashcard screen. Every kanji you meet in the narration quietly gets a memory card. Every sentence you write moves that card's review date: further out when you produce it correctly, closer in when you don't. Underneath runs FSRS, a modern spaced-repetition scheduler. It treats every reading of every kanji as a separate memory — so 食 known as しょく (食事) but not yet た (食べる) is tracked as two different things, because it is.
The kanji index
All 2,136 jōyō kanji as a living map of your memory. Cells tint by mastery band, hover for readings and JLPT level, click any cell for its per-reading breakdown, the sentences you met it in, and the words that use it. This grid is the game's real component over a real FSRS-simulated save.
The built-in IME
You type Japanese the way people in Japan do: romaji in, kana out, then kanji from a candidate strip. This is the game's real editor with its real input method, already in hiragana mode. Type sushi and watch it become kana as you go, then pick 寿司 from the strip. Ctrl+J cycles English, ひらがな, カタカナ. The built-in IME is there for everyone, but it's optional: if you already run an OS-level Japanese IME, it works here too. On this page the candidates come from a 15,000-word trim of the dictionary; in the game, from all 432,000+ entries.
The built-in dictionary
Look anything up the way you will mid-story: type Japanese or English, get readings, parts of speech, senses, and frequency rank. It's the game's real dictionary view — 432,000+ entries bundled offline in the game, plus 6,300+ human pronunciation recordings you can play on any word; on this page it runs on the same 15,000-word trim the IME above uses.
- 2,136jōyō kanji tracked
- 432,000+dictionary entries
- 6,300+pronunciations
The world
The world keeps honest books
The simulation is real enough to push back. The weather is actual climate history, hour by hour. Your body runs a full daily loop — hunger, thirst, fatigue — on its own schedule. Your wallet fills as you earn and empties as you spend, and what you can carry is bounded by the space and weight of whatever bag you've got.
The actual weather, hour by hour
Hourly weather reconstructed from real climate records, corrected for all 3,374 municipalities. A muggy Shikoku afternoon literally drains your thirst faster, the plastic umbrella in your bag exists for a reason, and this same forecast drives what happens next.
A body with needs
Your traveler runs on four vitals — fed, watered, rested, energized — each draining on the clock. Let one slide and the others follow: an empty stomach caps your stamina, and a tired mind starts swapping words — 食べました (ate) coming out as 飲みました (drank). Eating and drinking from your bag puts things right.
Every yen has a reason
You start with ¥250,000. Every yen in and out is a narrated event you can read back later — the ramen, the train fare, the day's pay. And the game never spends money you don't have: if the wallet's empty, the story says no.
Everything you carry counts
Slots and weight are set by the bag you wear — this messenger bag holds 12 slots and 10 kg. Items have weights, food has calories, and eating from the bag feeds the vitals above. The traveler on the left is cycling through a few of the characters the creator can build: height, build, 16 hairstyles, a recolorable 1994 wardrobe. What you're wearing changes how the weather treats you.
Getting around
Japan is the whole map
Every prefecture, all 3,374 municipalities, on official 1995 boundary data. You travel by saying so: take the train to Matsuyama, walk to the coast. You move along real adjacency, so there's no teleporting. The real weather follows you wherever you go — and Hokkaidō in February is a different game than Shikoku in May. This is the game's real atlas; zoom in, drag it around.
Where your traveler's dot ends up is between you, the train timetable, and your Japanese.
The AI
Models you pick
Lost Gaijin's story runs on language models, and the two roles — the Storyteller that writes the world and the Coach that grades your Japanese — each have their own model picker. Any modern model on the market can drive either one, and the defaults are tuned for the best balance of price and intelligence, so it plays great the moment you install it. The game itself is a one-time purchase: your copy arrives with a starter allowance of AI credits, you burn them down as you play, and when they run low you top up through Steam, without ever leaving the story.
The 14:10 for Imabari
Your station is waiting
One day of play is a fistful of kanji and a story you made yourself. A month is a traveler who orders ramen, asks directions, and reads the timetable's second column. Wishlist soon, get lost later.
Windows, Mac & Linux at launch · from Ten Turtle Games
Questions
Asked, answered
Do I need to know any Japanese?
You'll want hiragana and katakana before jumping in — that's the one prerequisite. Past that, it depends on your comfort with being uncomfortable: being lost is the point of the game. Day one is English, gestures, and pointing; the Coach translates what you meant into Japanese each turn, so the language arrives in the shape of what you were already trying to do. The more at home you are being lost, the more game you get.
How much does it cost?
A one-time purchase on Steam. Your copy ships with a starter allowance of AI credits; as you play, you burn them down, and when they run low you can buy more through Steam in-game purchases without ever leaving the game. Exact pricing will be announced closer to launch.
Which platforms?
Windows, Mac, and Linux at launch. It's a native desktop app, not a browser game.
When is it out?
It's in active development by a one-person studio, so there's no release date yet. Wishlisting on Steam will be the honest way to hear first.
Will it replace my Anki deck?
It replaces the half Anki can't do: using Japanese for real things under real pressure. The spaced repetition is built in, running on the modern FSRS algorithm and tracking every kanji reading you meet, so many players won't need a separate deck. But it genuinely depends on how you like to study. The game is the "use it" half, not the whole education.
What level is it for?
Beginner to intermediate is the sweet spot; the farther along you are, the more of each scene you'll read without help. The world doesn't simplify, but the Coach, furigana, dictionary, and inspector meet you at any level.
Does it need an internet connection?
Yes, for the AI. The story and the Coach run on language models. Everything else is local: the 432,000+ entry dictionary, the kanji index, the weather archive, and your saves all ship with the game.
Can I have multiple characters?
Yes. Each save is its own universe, with its own story, wallet, wardrobe, weather, and kanji progress. Keep as many parallel travelers as you like, exportable as a single file.
Gratitude
Standing on shoulders
Lost Gaijin is only possible because people built these projects for the love of it and shared them. The demos on this page run on their data, and if the game finds its audience, giving back to them is part of the plan.
Jitendex
Stephen Kraus's open Japanese-English dictionary, built on the EDRDG's JMdict/EDICT with example sentences from Tatoeba. Nearly every definition and kanji candidate on this page flows from it.
CC BY-SA 4.0KANJIDIC2
The EDRDG's decades-long volunteer effort to document every kanji. The index above is their work, made clickable. JLPT levels via Jonathan Waller's tanos.co.uk lists.
CC BY-SA 3.0Jiten
The Global frequency list: how common each word really is across novels, manga, anime, and drama. It orders what you meet first.
CC BY-SA 4.0ERA5 · Copernicus/ECMWF
The reanalysis dataset that reconstructs Earth's weather hour by hour. The forecast window above is real climate science, locally corrected with CHELSA (WSL) data.
CC BY 4.0MLIT 国土数値情報
Japan's National Land Numerical Information: the 1995 administrative boundaries every map on this page is drawn from.
CC BY 4.0MeCab & IPAdic
Taku Kudo's morphological analyzer and the NAIST dictionary. It is the reason every word in the story knows its own grammar. Built to WebAssembly by itayperl's mecab-wasm.
BSD · NAISTTofugu / WaniKani
6,300+ human pronunciation recordings for the dictionary. In the game, click a word to hear a person say it.
CC BY-SA 4.0Sakura Code & type
UlisesChoco's VS Code theme became the game's, and this page's, palette. Type set in Barlow, Barlow Condensed, Noto Sans JP, and Noto Serif JP (title).
MIT · OFLThe Open Source Supporter Edition
Includes a contribution to the Lost Gaijin Open Source Fund. This edition costs a little more than the standard game, and the supporter portion is set aside and distributed to the open-source projects above at the end of each year. You get the same game, and you help us give back to the developers and communities whose work made it possible.
Full legal notices
Jitendex (jitendex.org) by Stephen Kraus, adapted from the Yomitan term-bank format into a custom SQLite schema; no definitions edited. Upstream: JMdict/EDICT (EDRDG) CC BY-SA 4.0; example sentences © Tatoeba, CC BY 2.0 FR. The adapted database and derived datasets on this page remain CC BY-SA 4.0. The license applies to the dictionary data only, not to the game's code or other assets.
KANJIDIC2 © the Electronic Dictionary Research and Development Group (CC BY-SA 3.0), parsed from the XML distribution into SQLite. JLPT levels from Jonathan Waller's lists (tanos.co.uk) via the MIT-licensed davidluzgouveia/kanji-data aggregate.
Jiten Global frequency list (jiten.moe) CC BY-SA 4.0, parsed from the Yomitan term_meta format. Frequency ranks shown in the inspector demo derive from it.
ERA5 and ERA5-Land (Copernicus Climate Change Service / ECMWF), CC BY 4.0. Spatially subsetted to the Japanese domain, merged, area-averaged onto a 1.25° grid, quantized, and compressed: a modified product, not an original ECMWF product. Monthly corrections derived from CHELSA-monthly V2.1 (WSL), CC0. Neither the European Commission, ECMWF, Copernicus, WSL, nor MLIT endorses Lost Gaijin or accepts responsibility for the modified data or its use.
Administrative boundaries: 国土数値情報 行政区域データ (N03, 1995 vintage), Ministry of Land, Infrastructure, Transport and Tourism of Japan, CC BY 4.0. Polygons dissolved by prefecture and simplified; no boundaries redrawn beyond geometric simplification.
MeCab © 2001-2008 Taku Kudo / Nippon Telegraph and Telephone Corporation (BSD 3-Clause), compiled to WebAssembly via mecab-wasm; IPAdic under the NAIST / ICOT Free Software license. Runs at build time on this site and at runtime inside the game.
Pronunciation audio by Tofugu / WaniKani (CC BY-SA 4.0), bundled byte-unmodified in the game. Not redistributed on this page.
Sakura Code © UlisesChoco (MIT); a derived token palette ships in the game and on this page. Fonts: Barlow & Barlow Condensed (CARROIS) and Noto Sans & Noto Serif JP (Google), all SIL OFL.
Ten Turtle Games
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Lost Gaijin is the debut game from Ten Turtle Games, an independent Canadian studio.
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