Masahiro Setagawa is a sixteen-year-old high school student who initially appears as a hopeless and defenseless teenager. From a young age, he has been frequently used by neighborhood bullies as an errand boy, and he has been coerced into joining a local gang. His home life is troubled: his mother, Megumi Setagawa, works as a prostitute, and Masahiro has a strained relationship with her, disagreeing with her profession and being forced to become independent early on. His father is absent, either having left the family or died when Masahiro was young. Because of these experiences, Masahiro has stopped believing in heroes, finding the concept unrealistic and believing that no one will ever save him. He has a tough exterior but a soft heart, and he often feels helpless and resigned to his circumstances. However, his life changes when he meets Kousuke Ohshiba, a man known on the streets as the Bear Killer for his fighting abilities. Kousuke saves Masahiro from his gang and later becomes his math teacher as well as the older brother of Masahiro’s best friend, Kensuke Ohshiba. Masahiro comes to view Kousuke as a hero and develops romantic feelings for him. His motivations center on wanting to be protected and to find a sense of belonging, and he gradually learns to accept love and trust. Throughout the story, Masahiro undergoes significant personal growth, moving from a passive and resigned delinquent to someone who can believe in and pursue a genuine connection. His key relationships include his romantic involvement with Kousuke, his close friendship with Kensuke, and his complicated feelings toward his mother. Masahiro does not possess any supernatural or special abilities, but he is resilient and capable of deep emotional loyalty. Physically, he stands 176 centimeters tall, weighs 67 kilograms, and has blonde hair and small green eyes. He wears a chain necklace and has ear piercings, later adding a ring to his necklace. His birthday is January 15.