Hikaru has a couplw of really good friends that help a lot. One of there names is Isumi. He is an insei which means pro go player. He knows where a lot of Go salons are so he and Hikaru can brush up on their skills. His other friends name is Waya. He's one of Hikaru's classmates at the inei school. Both of them are studying to become professional Go players.
Sai is a ghost that used to play Go in ancient times. No one can see him except Hikaru because he awakened him. He plays Go through those who awaken him so that means Hikaru has an unfair advantage against the other players.
Akira Toya is a Go legend and he is the same age as Hikaru. Akira has been Hikaru's rival ever since he lost a game to Sai who played through Hikaru to help him win because the last time Akira and Hikaru played Go Hikaru lost and Akira said that he was pitiful and not even worth playing. Hikaru didn't want Akira to feel like that this game so he won using Sai. After that match Akira went crazy and he said there was no way he could have won and he pledged that he'd find out how he did it.
One time korean Go pros came to Japan. Hikaru was an idiot and said that he'd never heard of korean pros before. After he said that a young pro got really mad but he stayed calm and sat down. Hikaru asked him if he was challenging him to a game. The young boy told him that it would be better practice to play anyone else in the Go salon then to play him. After that Hikaru got really mad and sat down to. He told the kid choose a color and they started to play. Once they started to play the Korean kid was making one good move after another. Hikaru was doing the same. Then HIkaru made a bad move or so the other pro thought, but it turned out that Hikaru was setting up a move that would put him in the lead. When the match ended Hkaru reigned victorious by one and a half points.