Gaku Yashiro

Initially, Gaku is presented as a kind, charismatic and understanding teacher who is popular with his students as he is always willing to help out. In addition, he tries to defend his students when they are wrongly accused, such as when Misato Yanagihara accused Kayo Hinazuki of stealing her lunch money. He even helps out Kenya Kobayashi, Osamu, Hiromi Sugita and Kazu with their birthday scheme by making Kayo and Satoru stay late at school so that the group could prepare surprise. However, beneath this facade laid an evil, very selfish, deplorable, sadistic amoral psychopath. He was very methodical, ensuring two conditions were met: first, that he had someone he could frame and second, there would be a period where the person was alone. He also killed those who he saw had a spider string above their heads. His desire to kill seemed to stem from his childhood along with an experience where he drowned a group of hamsters and saw one alive while standing on one of the corpses of his fallen brethren. Gaku plans out all of his murders and ensures no evidence leads back to him while distancing himself from the incident in one town before moving to a new one. Yashiro carefully thought out his plan that he killed Hiromi Sugita, a feminine-looking boy, to make it appear as if the killer's only interest was in females by mistaking the boy for one.