Yu Ishigami is the fourth member of the student council. Despite being a first-year, he was scouted out by Shirogane for his talent with numbers and appointed the council's treasurer. Owing to Yu's introverted personality, he normally doesn't stand out much, but the council would fall apart without him. But one day, Yu goes to Shirogane and confesses his desire to quit the group. In fact, his mind is made up, even though Shirogane desperately tries to persuade him to stay. Apparently, the situation is beyond Yu's control, but with a tear in his eye, he explains to the president that he thinks he's being targeted for murder... (thetvdb.com)