Sagak — Shikaku Logic Puzzle

Pencil lines drawn on paper. Divide the grid into rectangles, match each rectangle to its number,
and the sheet is done. Every finished board is printed as a stamp and filed in a monthly album.

■ What is Shikaku?
Shikaku (also written sikaku, or "divide by squares") is a logic puzzle played on a grid of numbers.
The rules are two lines:
· Every cell belongs to exactly one rectangle.
· Each rectangle contains one number, and that number is its cell count.
There is always exactly one answer. Nothing has to be guessed.

■ One sheet a day
A new sheet arrives every morning. The same date gives the same board on every device.
Solve it late and it still fills that date. An empty day is not a failure — it is a space left open.

■ Hints that teach the reason
A hint never places the answer for you. It names the one step that is certain right now,
explains why in a sentence, and lights the cells the deduction rests on.
Eleven techniques, learned one at a time.
Reach a dead end and only the wrong blocks are removed; everything correct stays on the board.

■ Something stays in your hand
A solved board is printed as a stamp, and the layout of your rectangles becomes its pattern,
so no two stamps repeat. Stamps are filed by date in the monthly album,
and boards with a notable shape fill entries in the pattern codex.

■ 12 notebooks, 240 sheets
The Journey runs 12 notebooks of 20 sheets. Fill one and the next opens.
Free play spans 5×5 to 13×15 across five pencil grades — HB, B, 2B, 4B and 6B.

■ Your desk
Boards solved, share finished without hints, average time per board, longest run of days,
and the techniques that still cost you hints — all on one screen, kept on your device.

■ How it feels
Drag to draw a rectangle, tap to erase it. Four tools only: undo, redo, hint and wand.
Touch, sound and haptics answer in the same frame.

■ Made for
· Ten to twenty quiet minutes on a commute or before sleep
· Sudoku and nonogram solvers looking for a new rule set
· Anyone who likes a record that grows a little each day

■ Questions
Q. Does it need an internet connection? Solo play works without an account or internet connection. Solo progress and stamps stay on your device.
Q. Can a board have more than one answer? No. Every board is checked for a single answer and for a pure logical path.
Q. Is there a timer? Solo play has no time limit. Online matches compare completion times on the same puzzle and have a time limit.
Q. Which languages? English, 한국어 and 日本語.

■ Accessibility
Large type, dark mode, contrast options and screen-reader support for the board.

Online play requires a connection and separate consent. An anonymous account, nickname, flag, rating and match records are stored on the server and can be erased in Settings.