Name : Tsutsui
A typical nerd boy ^o^ that's what shown by his first impression. With a huge thick glasses, calm, and carrying GO strategy book everytime he plays GO. Tsutsui indeed a very patient and lightheated person, he built the first ever GO club in his school all by himself.
His love into GO was truly shown as he get outraged when Kaga Tetsuo put a cigar on the GO ban. Tsutsui is indeed a Yose master and honest player, that's why he doesn't agree to enroll Mitani Yuuki in his GO club because he believes playing GO is about to trust your opponent.
Shindou Hikaru knew Tsutsui, who's later became his senpai, in such a coincidence when he was waiting for Fujisaki Akari in the Haze Junior High School Fair. At the time, Tsutsui held a GO quiz with the final prize : a "100 GO Strategies by Touya Meijin" book. Since Fujiwara no Sai was so urge to have the book so he provoked Hikaru to try it. There Hikaru tried his first own GO solution. And things get tough when Kaga interrupted, until Hikaru was even involved in a brawl. But due to this incident, Hikaru started his GO adventure. Later on Hikaru enrolled in the same school with Akari, Tsutsui, Kaga, and Mitani.