LEADERBOARDS
- Ichi · Ni · SanBest time per difficulty.
- Daily ChallengeOne puzzle a day, ranked against everyone.
- All-time PointsCumulative across every solve.
難しい · Muzukashii · "difficult"
See Less.
Think More.
A standard nine-by-nine board hides behind the screen. Only the three-by-three you're working on is visible — the rest live in your head. Swipe between boxes, or tap the mini-map to wander.
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Three difficulties
Ichi, Ni, San. Pick your tier and resume right where you stopped.
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Daily Challenge
A new daily puzzle for everyone. Keep your streak alive with the calendar tracker.
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Zen mode
Play freely. No timer, no records — just the board.
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Pencil notes
Add candidate digits to a cell. Placing a digit removes conflicting notes automatically.
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Conflict arrows
Even unseen parts of the board respond — a red arrow points to a duplicate hidden in another box.
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Koyo-inspired atmosphere
Washi paper, sumi ink, soft ambient music, and a page flip when switching regions.
Game Center
Climb the boards.
Collect the marks.
ACHIEVEMENTS · 11
- First LightSolve your first puzzle.
- FlawlessSolve without ever creating a conflict.
- By Memory AloneSolve without enabling Notes.
- StreaksSeven, thirty, one hundred days.
- and more to discover ...
♥ SUPPORTER EDITION
A voluntary one-time support for the game. The app stays fully playable without it — nothing behind the gate is required to solve a puzzle.
As a thank you, you get:
- Dark modeThe same scene at dusk — Sumi surfaces, Momiji red lifted into a glow.
- Alternate app iconA second mark for the home screen.
- Custom splashA different opening frame on cold launch.
- Supporter badgeA small pill on the main menu.
- More to comeFuture premium features — new themes, extra puzzle packs and seasonal palettes — arrive at no extra cost.