I might be able to refresh your memory a bit. Hikaru no Go is about a boy named Hikaru who along with a friend of his comes across a go board in his grandpa's attic. Hikaru thinks he sees blood on the board and tries to clean it off (I think that's how it goes) and he meets the ghost of a notorious tutor of the Fujiwara clan.
The tutor, Fujiwara no Sai committed suicide after being wrongfully accused of cheating during a game of Go. So, Hikaru and Sai make a pact that he will help Sai pass on by playing the ultimate Go move since Hikaru's predecessor passed away before playing the move that would help Sai move on.
The tutor, Fujiwara no Sai committed suicide after being wrongfully accused of cheating during a game of Go. So, Hikaru and Sai make a pact that he will help Sai pass on by playing the ultimate Go move since Hikaru's predecessor passed away before playing the move that would help Sai move on.