Kazuya Miyauchi

A popular and attractive boy in Nanoka's class. He's initially introduced as a possible rival for her affections, but in the manga he has a forbidden love of his own and is infatuated with the school librarian. Unlike Futaba or Tamaki, Miyauchi does not tease Nanoka about her "brother complex" and tells her not to take their jokes to heart.

(source: Opentopia)