Tetsuo Kaga (加賀鉄男, Kaga Tetsuo) is the president of Haze Middle School shogi club.
He is first seen as a disruptive teen until he invites Hikaru to be apart of the Go Club. This and later events shows how even though he is rather sarcastic he is a good person and protective of his friends.
As a child Tetsuo was a very devoted Go player (mainly because of his father's insistence) until he lost to Akira Touya. This, not only led to him losing his father's attention. However, Tetsuo is a very good and well versed shogi player.
Although Tetsuo played only a few games in the series he is apparently a very strong player even beating Hikaru (actually Sai). He is able to grasp his opponent's strength and moves fairly quickly.
Although he is destroyed Tsutsui's Go Stand at the festival the two seem to have a close relationship with each other.
He first meets Hikaru at a festival and finds out how strong Hikaru (again actually Sai) is. The two eventually become friends when Hikaru fakes being a middle schooler to be apart of Tsutsui's Go Club
When Tetsuo played Go he considered Akira his rival and seems to have a passionate dislike for both Akira and his father.