Washizaki Kei

The protagonist of the story, a 22 years old fourth-year college student. Born into an ordinary family, and possesses a few talents. Due the his athletic skill and his talent in just about anything, he is often relied on by those around him. In June, during his fourth year at his college, he is an honors student who has already got a job offer from a large company. Since childhood, for many years, he has been in love with his younger sister Haruka.

"To protect the gentle smile of Haruka, our family and the world have to recognize our relationship, so us siblings can be tied together."

To fulfill this wish, he has devoted himself since elementary school, searching for the means (Answer) alone. In his mind, one is an adult who must face a rational logic and the reality, on the other, a child who cannot forget his feelings for his sister, contrary to his calm appearance, his mind is extremely unstable. He hates the world for not approving of their relationship, just because "they are siblings", and no other reason. Moreover, while he is convinced that he truly loves his sister, he has to give up because it might bring sorrow to her, still, he despises himself more than the world itself for not being able to give up completely.