After stumbling across a haunted go board, Hikaru Shindo discovers that the spirit of a master player named Fujiwara-no-Sai has taken up residence in his consciousness. Sai awakens in Hikaru an untapped genius for the game, and soon the schoolboy is chasing his own dream--defeating the famed go prodigy Akira Toya!

Hikaru ignores Sai's pleas to let him play go, and then one day Sai vanishes! Is he mad at Hikaru? Where has he gone? Will he ever come back? And will Hikaru be able to play without Sai's coaching...?