MASYU: Loop Logic Puzzle

Two rules, endless calm. White goes straight, black turns—link every pearl into one loop. Always exactly one solution. No numbers, no noise. A quiet daily puzzle.

One line. A clear mind.

MASYU is a quiet logic puzzle: link every pearl on the board into a single loop that never crosses or branches. No numbers, no math—just two simple rules and your finger.

Two rules, real depth

• White circle ○: the line passes straight through, and must turn in the cell just before or after it.
• Black circle ●: the line turns on the circle, and goes straight through the cells on both sides. From these two rules, surprisingly deep boards emerge.

Features ◆ Four difficulties (Easy / Medium / Hard / Expert) ◆ A fresh Daily Puzzle — the same board for everyone, every day ◆ Every puzzle is uniquely solvable, verified by a real solver—no guessing required ◆ Fully offline, no account, no sign-up ◆ A gentle hint for when you're truly stuck ◆ Records & streaks: solves, best times, no-hint rate, daily streak ◆ Calm, paper-and-ink design in indigo and vermilion

Great for you if

• You've solved enough Sudoku and want a new kind of logic puzzle
• You want to reset your mind during a commute or a short break
• You're tired of ads and notifications and crave quiet focus
• You like building a small daily brain-training habit
• You enjoy Nikoli-style pencil puzzles (loop / one-stroke)

Privacy

• No account required.
• Your records stay on your device—nothing is sent to any server.
• Works fully offline.