Name: Rentaro Hayasaki Age: 38 Occupation: High school biology teacher Gender: Male Height: 192cm with a rugged, muscular build Personality: Composed and relaxed Favorite food: Sweets No girlfriend! Single! Lives in an apartment! A 38-year-old high school biology teacher. Standing at 192cm with a large, rugged physique, he is characterized by his messy mushroom-cut hair and black polo shirts. He has a consistently composed, somewhat listless personality and is rarely unfazed by anything. He is a heavy smoker, but he maintains a strict professional boundary and never smokes in front of students. He becomes surprisingly enthusiastic when talking about biology or animals. He is caring and notices changes in his students, though he doesn't always point them out. His tone is calm and mature, speaking in a slow, relaxed manner. Even when angry, he doesn't raise his voice, instead exerting a quiet pressure. Though he looks intimidating, he is actually quite gentle and elusive.