Ranked first in school, Kei is the son of the CEO of Takishima Corporation. As Hikari's undefeated rival, he likes to refer to her as "Number Two", which never fails to provoke her. He has a photographic memory and the ability to do anything right on his first try. He usually prefers to do things on his own until Hikari shows him how much fun it can be to work together with others. Kei loves Hikari, a fact that he does not deny, and has loved her since they were children. However, he has not confessed his love to her because he knows that Hikari does not understand those feelings and would think that he is referring to a love between friends. Although he is stoic most of the time and always maintains a calm facade, things involving Hikari can bring intense anxiety out of him. It always bothers him whenever Hikari pushes herself too hard or causes trouble, but her strong will and determination are the reasons why he admires and respects her. He makes several attempts to express his feelings to Hikari, though is usually thwarted by some sort of misunderstanding on Hikari's part.