Kai

Kai is an eighteen year old high school student with no particular goals or ambitions in life. He is still emotionally immature, and is not ready to live as an adult. He relies on his best friend Chris more than he realizes, though to her chagrin, he has a hard time seeing her as a member of the opposite sex. Conversely, Kai has a crush on Sophie, despite knowing very little about her, but lacks the courage to converse with her properly. [From Official site]