Summary
Isumi, Shinichiro is a fellow insei and friend of Hikaru who initially demonstrates exceptional skill by remaining undefeated in the first professional examination depicted in the manga. His perfect run ends during his match against Hikaru, where the combination of time pressure and rumors regarding Hikaru's formidable strength causes Isumi to lose focus and misplace a stone. In his attempt to correct the error after letting go of the piece, he resigns the game before Hikaru can even accuse him of cheating. This defeat triggers a slump, causing him to lose his subsequent two matches and eliminating his opportunity to become a professional that year. However, Isumi eventually learns to master his emotions and successfully passes the following year's professional exam without suffering a single loss. Additionally, he inadvertently aids Hikaru in coping with the loss of Sai; their practice game helps Hikaru realize that he can find Sai within his own moves, accessing the Go that Sai passed on to him. Isumi's birthday is April 18th.
