Seiichirō Usami

Seiichirō Usami (宇佐美 誠一郎 Usami Seiichirō), reluctantly nicknamed "Pyon-kun", is the older brother of Ikue Usami who is extremely overprotective of his sister and has demonstrated some excessive interest in her and her friends. Yuki Kurihara uses this to her advantage, bribing him with pictures of his sister and her friends in exchange for info on Shinya Momotsuki's schedule.

Trivia

 * The name Seiichirō means "sincerity" (誠) (sei), "one" (一) (ichi) and "son" (郎) (rou).
 * Seiichirō's surname Usami means "eaves, heaven, house, roof" (宇) (u), "help, aid" (佐) (sa) and "beautiful" (美) (mi).