Tomio, formally Ryuji Tomioka, is a close friend of Kenji Yamaguchi. He attends an all-boys high school and forms part of a tight-knit group comprising Yamaken, Ma-Bo (Masahiro Ayanokoji), and George (Issei Jojima). Sharing a high-society background, the group frequently engages in activities highlighting their privilege. Tomio and his friends openly admire Asako Natsume, expressing their attraction to her, and refer to Shizuku Mizutani as "Nerd Queen," showcasing their penchant for playful teasing. Their interactions with Yamaken in social settings fuel recurring comedic scenes, marked by collective admiration of female characters and commentary on school life. Tomio possesses light spiky hair, distinguishing him within his circle.