Initially, Tooru seems to be a very jealous type of person which is shown when he was glaring at Miyamura when he talked to Hori. He has a very explosive temper as seen in Chapter 12 when he ends up fighting with Miyamura when he (Miyamura) kept waving off Ishikawa's constant pressing on of his theories on whether or not Hori has a crush on Miyamura. However, he expresses regret about losing his temper after the fight.