Yuuji Arihara is Ayumi Arihara's older brother. His closest friends are Bessho Yoshihiko and Chikura Kazuma of the same grade. He is shown to have a sister complex and is often found fighting with Bessho Yoshihiko on whose sister is more attractive (Yuuji is most often the one who initiates the fight). He is a carefree individual who can seem quite idiotic at times. Yuuji eventually becomes the love interest of Yamamoto after Yuuji force fed her a lollipop as a demonstration to Bessho of a daydream he had of Ayumi and Misao Zaitsu. In the end he seems to have returned Yamamoto's feelings.