Masyu (Pearl Necklace) is a loop puzzle with white and black pearl constraints. White pearls: straight through, turn in an adjacent cell. Black pearls: turn in the pearl, straight in both adjacent cells. Elegant and visual, with a famous naming mix-up.
ルール
Draw one loop through every pearl. White pearls: path goes straight through but must turn 90° in at least one adjacent cell (before or after). Black pearls: path must turn 90° in the pearl, then go straight through both neighbouring cells. Loop is single, closed, non-crossing. Solve by logic; unique solution. Corner black pearls fully determine the path; two adjacent black pearls force a long straight; white on an edge forces the turn inward.
歴史
Nikoli 2000 as "Shinju no Kubikazari" (Pearl Necklace, white only). Reader suggestion added black pearls; renamed "Shiro-Shinju Kuro-Shinju." Nikoli CEO Yoshinao Anpuku misread the kanji as "Masyu" (evil influence)—adopted as the official name. Global puzzle books and apps.
戦略のヒント
Corner black pearls are fully determined—solve them first. White pearl with one open direction (edge or black cell) forces the turn. Resolve all "forced" pearls before tackling ambiguous ones. Two adjacent black pearls force a long straight; use that to extend the loop.
文化的背景
Beloved for elegant constraints; the accidental "evil" name is a famous puzzle-community story. Widely published in Western puzzle books; strong digital presence. Masyu (Pearl Necklace) started with white pearls only; a reader suggested black pearls and the puzzle was renamed. The CEO misread the kanji as "Masyu" (evil influence)—and that became the official name. Play at Nikoli.com, Conceptis Masyu, and Simon Tatham's Portable Puzzle Collection.
購入・プレイ
- Masyu Puzzle Book (Nikoli) Official Nikoli masyu collection
- Play Masyu free online (puzzle-masyu.com) Free daily Masyu puzzles, multiple sizes and difficulty levels