Shuusei Iizuka, Kenta's father & Fumio's ex-boyfriend

Shuusei Iizuka (飯塚 修成, Iizuka Shūsei) is Kenta Usui's father. He and Fumio conceived Kenta while still in high school which enraged Fumio's mother. He was barred from contact with Fumio or Kenta. He and Kenta look very much alike, with the exception of a scar above Shuusei's left ear, shown in an omake to have been given to him by Fumio at a young age when she pushed him into a jungle gym. He locates Fumio and Kenta by following a detective named Yonehara (米原), who was charged to find Fumio by her mother, wanting to apologize for the past. He notes that he is dating a woman now who is pregnant, and he does not intend to repeat the mistakes he made with Fumio