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 faces the preliminary rounds of the pro test, during which he must eliminate not only his classmates at the insei school but also any outsiders who want to take the test. One of them in particular appears to know how to exploit Hikaru's weaknesses, and poor Hikaru seems powerless to stop him.