Reiko Minami

She was a middle school teacher and the object of Sakaguchi's affection. She used to teach at a local middle school where Sakaguchi has been studying (which suggest that he was been there as a repeat student for quite a long time). She later on moved back to Tokyo after Sakaguchi in a fit of drunken stupidity forcefully drag her into one of his misdemeanors that eventually got him arrested. It also inadvertently jeopardize her reputation as a teacher in the town's middle school. Despite it, she forgave him and doesn't file any charges against him. She still sees hope in him in spite of his rowdy behavior.

(Source: ANN)