Credits & Sources
Every dataset, photo, and music track used across this site's tools, credited in one place — the short version lives in every page's footer, this is the full version.
Licensing
This site's code is MIT licensed. Three of its data files — game-words.js, phonetics-data.js and phonetics-kanji-index.js — carry kanji phonetic-component data derived from Kanjium and are therefore offered under CC BY-SA 4.0, the same licence Kanjium uses. The full terms, including the third-party notices, are in the LICENSE file.
Dictionary & language data
- Kanjium — CC BY-SA 4.0 · kanji & phonetic-family data
- Tatoeba — CC BY / CC0 · example sentences
- scriptin/kanji-frequency — CC BY 4.0 · usage ranking
- elzup/jlpt-word-list — vocabulary curation and JLPT level labelling
Bundled typefaces & code
- Fraunces — SIL Open Font License 1.1
- IBM Plex Sans — SIL Open Font License 1.1
- supabase-js 2.115.0 — MIT
These are served from this site rather than from their vendors’ content networks, so that opening a page doesn’t send your IP address to a third party. The font licence text ships alongside them in fonts/OFL.txt.
Kana Origins — historical photography
- Kofun-era haniwa figurine — Gary Todd, CC0
- Inariyama sword inscription — 斑猫, CC0
- Kojiki, Shinpukuji manuscript — Ken’yu (賢瑜), 1371–72, public domain
- Hakubyō Genji monogatari emaki — unknown author, public domain
- Lotus Sutra vol. 8, Heian period — Daderot, CC0
- Yokohama harbour woodblock print — Utagawa Yoshikazu, CC0
- Ginza, c. 1960 — unknown author, public domain
All sourced from Wikimedia Commons, resized and re-compressed for use here; no other changes made. The read-order diagram in the same section is drawn in HTML rather than reproduced from any source.
Word Game — background photography
- Himeji Castle — Gorgo, public domain
- Matsumoto Castle — 663highland, CC BY 2.5
- Osaka Castle — 663highland, CC BY 2.5
- Kumamoto Castle — 663highland, CC BY 2.5
- Nagoya Castle — Bariston, CC BY-SA 4.0
- Hikone Castle — ロロ (Roro), CC BY-SA 3.0
- Mount Fuji (aerial) — Hghask Ekorb, CC0
- Mount Fuji & Lake Kawaguchiko — Midori, CC BY 3.0
- Mount Tate & Mount Tsurugi — Alpsdake, CC0
- Mount Shirouma — Alpsdake, public domain
All sourced from Wikimedia Commons, resized and re-compressed for use here; no other changes made. Each level uses one of the ten photos above, cycling every 10 levels, shown faded behind the board.
Word Game — background music
- Soul Jazz Restaurant
- Soul Jazz Coffee Shop
- Soul Jazz Study Session
- Soul Jazz Rainy Night
- Soul Jazz Midnight Club
- Soul Jazz Sunny Cafe
- Soul Jazz Cocktail Bar
- Jazz Study — Study Music
- Study Jazz — Study Music
- Jazz Study Music
- Saxophone Jazz Study Session
- Samba Jazz Study Session
- Jazz Study Session Music
- Jazz Lounge Study Music
- Swing Jazz Study Session
- Smooth Jazz Restaurant
- Smooth Jazz — Coffee Shop Music
- Smooth Jazz Lounge — Relaxing Evening
- Smooth Jazz Midnight Club
- Smooth Jazz Coffee Shop
- Smooth Jazz Rainy Night
- Smooth Jazz Study Session
- Smooth Jazz Cocktail Bar
- Lofi Jazz Trio Sunny Cafe
- Lofi Jazz — Study Music
- Lofi Jazz Retro Coffee Shop
- Lofi Jazz Melody Restaurant
- Lofi Jazz Soulful Midnight Club
- Lofi Jazz Swing Cocktail Bar
- Lofi Jazz Smooth Study Session
- Jazzy Pop Piano / Japan City — WELC0MEИ0
All 31 tracks via Pixabay Music, used under the Pixabay Content License (free for commercial use, no attribution required — credited here anyway). Re-encoded to 112kbps for file size; no other changes made. Soul jazz plays on N1, jazz-study on N2, smooth jazz on N3, and lofi jazz on N4 & N5 (shared pool), cycling by level within each tier; the 30 tier tracks are by Alex-Beats (Alex Morgan), except Jazzy Pop Piano / Japan City by WELC0MEИ0, which plays on the level-select screen while browsing between levels.
Word Game — night backgrounds (dark mode)
- Himeji Castle — Corpse Reviver, Public domain
- Matsumoto Castle — Luka Peternel, CC BY-SA 4.0
- Osaka Castle — Tokumeigakarinoaoshima, CC BY-SA 4.0
- Kumamoto Castle — Uploaded to wikipedia by Vickerman625 on 23 July 2007 and up, CC BY-SA 3.0
- Nagoya Castle — 名古屋太郎, CC BY-SA 4.0
- Hirosaki Castle (shown where the daytime set has Hikone) — 掬茶, CC BY-SA 4.0
- Mount Fuji from Kawaguchiko — Sergiy Galyonkin, CC BY-SA 2.0
- Mount Fuji under Polaris — Victor Porof, CC BY-SA 3.0
- Milky Way from Mt. Chōgatake — Daisuke tashiro from Japan, CC BY-SA 2.0
- A mountain under the stars — Mehmet Kürşat Değer mkd, CC0
Shown in place of the daytime photographs above when the site is in dark mode. Sourced from Wikimedia Commons, resized and re-compressed for use here; no other changes made. No night photograph of Hikone Castle exists on Commons, so that level shows Hirosaki Castle instead.
Grammar Connect — background photography
- Tokyo by Night — Nalilord, CC BY-SA 3.0
- Minato City, Tokyo, Japan — David Kernan, CC BY 4.0 (the daytime sky, shown in light mode)
Sourced from Wikimedia Commons, resized and re-compressed for use here; no other changes made.
Grammar Connect — background music
- Cozy Lofi Chill — Soft Vlog Beat, Smooth Relaxation — Music_for_Videos
- Ancient Garden — Zen Lofi — Turning Pages
- Zen Drift — Turning Pages
- Japanese Lofi Beat — Cozy Chill Vlog, Soft and Smooth — Music_for_Videos
- Lofimercurius — lofi_nemuko
- Lost Train — Papulina (Ivan Luzan)
- Slowburn — Relaxing Lofi Background Music — joelfazhari
- Japanese Lofi Jazz — Calm Piano Beats, Chill and Smooth — Music_for_Videos
- Japan — Japanese Music — Mirostar
- Asian Lofi Hip Hop 04 — VJGalaxy
- Asian Lofi Hip Hop 08 — VJGalaxy
- Asian Lofi Hip Hop 10 — VJGalaxy
- Fireflies in the City (1 Min Edit) — Japanese Fusion Lofi — Kaazoom
- Petals on the Water (Full Version) — Japanese Fusion Lofi — Kaazoom
- Tokyo Bridge Dream — Lofi Chill Music with Bells — Monkey Bandito
- Zen Garden Beats — eggshy
All 16 tracks via Pixabay Music, used under the Pixabay Content License (free for commercial use, no attribution required — credited here anyway). Three tracks cycle per JLPT tier (N5 through N1); Zen Garden Beats by eggshy plays on the level-select screen while browsing between levels.