Kotoko has liked Irie Naoki first year in highschool, at first Naoki thought of her as "annoying", but eventually he falls for her. During the first year entrance ceremony, Kotoko fell in love with Naoki, time passed by and she united all her courage to give him a love letter, wich he rejects. This rejects deeply hurts Kotoko. Later, when Kotoko's house collapses, her father moved to his old friends house, which was Naoki's dad. Lots of things happen to Kotoko during that time in Irie's house. After some time Kotoko found out about Irie and he's contract marriage, and eventually Kinnosuke (Kin-chan) proposed to Kotoko. When Naoki found out about this after picking her up, he kissed her and also askes her to marry him and she accepts, they eventually marry and he faces some challenges. At the end they had a beautiful girl named Irie Kotomi.
Satomi is one of Kotoko's best friend from class F.
Jinko is one of Kotoko's closer friends. She had class F with Kotoko and Satomi.
Shigeo is Kotoko's father and is known throughout the story to be very accepting and supportive of his daughter, moving back to the Irie household when he saw how down Kotoko got. He also gave his blessing of the Marriage of Kotoko and Irie Naoki.
Noriko Irie is Naoki's mother and shes been very fond of Kotoko since they met. She's usually seen trying to get them together by conveniently placing them together alone and such.
Yuuki is Naoki's younger brother and has been called a, "Miniature Naoki" by Kotoko. He's very intelligent and not good at expressing his feelings. He didn't like Kotoko at first, but warmed up to her. She saved him from drowning and another incident and Yuuki watched Naoki kiss Kotoko, knowing then that he loved her and supporting it throughout then. Although always calling Kotoko names, he still cares about her.
Kotomi is Naoki and Kotoko's daughter. Although she competes with her mother for Naoki's attention, she still cares a lot about Kotoko and vice versa.