2026-08-03 · history
Masyu (2000) — The Loop of Black and White Pearls Born from a Misreading
In April 1999, Puzzle Communication Nikoli issue #84 published a puzzle format called "Pearl Necklace," using nothing but white circles. In 2000, issue #90 added black circles and renamed it "White Pearl, Black Pearl," completing the logical skeleton Masyu still uses today. The official name "Masyu" wasn't settled until 2003 — the result of Nikoli's president misreading a kanji, an accident that simply stuck. With sources, we trace how a grid using no numbers or letters survived 26 years across an NP-completeness proof, official console ports, and an open-source implementation.
