Hikaru Shindo, an ordinary sixth-grader in Japan, finds an old Go board in his grandfather's attic that holds the ghost of Fujiwara-no-Sai, an ancient Go master who once taught the game to the Emperor of Japan, and somehow Sai becomes part of Hikaru's consciousness, making them an unstoppable Go-playing team.
Hikaru Shindo, a schoolboy whose consciousness houses the spirit of a master Go player, struggles to turn his losing streak at the insei school around in time for the Young Lions Tournament, where he could have a chance to play against his rival, Go prodigy Akira Toya.
Hikaru, gaining expertise from the spirit of the game master Fujiwara-no-Sai, agrees to play Toya Meijin online, but if he loses he must reveal his identity, then he takes on an opponent who uses the same color stones.
Hikaru Shindo, who stumbled across a haunted Go board and lives with the spirit of a master player, Fujiwara-no-Sai, in his mind, refuses to let Sai play, which causes the inner coach to vanish, leaving Hikaru to fend for himself.
