The main character of the story, Haine was actually born to the Kamiya family. In 4th grade she was sold by her real father and/or adopted by the Otomiyas. She is not exactly the smartest person in the world, but has a good heart. Back in her 9th grade she was a former " Yanki" or young delinquent and was known as "Cinderella of the beach". But after she met Shizumasa (her first love) Haine changed her ways so she could go to the same school as him and meet him again.
Once she finds out Takanari is posing as Shizusama, she has to wrestle her feelings for the both of them. She stated that when the time comes, she will choose one of them. As of Chapter 34, it is a known that Haine is the daughter of Itsuki (her father in the Otomiya family) and Maika (mother in the Kamiya family). Out of pain of this discovery, she becomes a delinquent again at the end of Chapter 35.