Yūma Isogai

Yūma Isogai is a student in Korosensei's Class 3-E at Kunugigaoka Junior High School. He is the male class representative. Isogai has somewhat spiked black hair with two small hair antennae at the top and brown eyes (pale gold in the anime). In addition to his personality, Yūma has been described as being very attractive and is one of the most popular members of Class 3-E. He's also popular with others from the main building and still receives love letters from females there despite the otherwise general discrimination.

Isogai is a kind, cheerful, and reliable person. He is modest, not at all boastful, and helpful. Isogai has been noted to have good leadership qualities and personal virtues, and due to that he's able to see all the individual strong points in his classmates. Because of these traits, he is considered to be an ikemen, which not only means handsome, but can also imply a flawless personality. Isogai comes from a poor family.

He has an unnamed younger brother and unnamed younger sister who happen to have the same hair hair antennae as him and lives with his sick mother. His father died sometime during his first year in middle school, leaving him to take care of his mother and their finances. To keep their expenses from going up, especially from their combined tuition struggles, Isogai began working part-time despite knowing that school regulations stated students weren't allowed to have jobs. At some point he was caught and unlike many of the students in Class E who landed there due to poor grades, he was put in there for violating that regulation.