Haru Asai is a main character in the anime Eikyū Shōnen Eternal Boys NEXT STAGE. He is a former professional soccer player who, after the end of his athletic career, finds a new purpose as a member of the idol group Eternal Boys, which is composed of middle-aged men. At 35 years old, Haru stands 170cm tall and has B-type blood.

Before becoming an idol, Haru dedicated his life to soccer. After graduating from high school, he built a career as a professional player, where his natural talent for scoring goals was his most prominent asset. However, his time on the field was cut short due to an injury, which marked the beginning of a steady decline in his athletic performance. He was eventually outpaced by both his peers and younger, rising players. At the age of 34, he received the official notice that he was being dropped from the team roster, forcing him to confront the end of the only career he had ever known.

Haru possesses a fiercely competitive spirit and harbors a deep-seated hatred for losing. This drive, while a key part of his identity as an athlete, also makes him prone to getting carried away easily. Beyond his professional life, Haru has personal responsibilities that distinguish him from other members of the group. He is a divorced father, which makes him the only parent in Eternal Boys. This aspect of his background likely influences his motivations and adds a layer of maturity and real-world pressure to his pursuit of a second career in entertainment. His name, Haru, can signify permanence, while his surname, Asai, combines characters for shallow and well or pit.