MASYU: Loop Logic 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.