Chiaki Kounoike

Bob's girlfriend with a very open mind. Although she never stood against Souichiro and Bob' street-fighting, she opposes them after their joining with the Juken Club. After hearing the story about Maya and Mitsuomi's relationship, she starts to think that Maya's ego is what drives everyone around her to be miserable. When Bunshichi explains the whole story, Chiaki decides to give support to the Juken Club, still believing that Maya's stubbornness is what caused the past events to occur.(Taken from Wikipedia) Chiaki seems to love having intercourse with Bob, this is evident in most chapters that feature her character as she is usually have sex with Bob.

She even went as far as asking Bob to quit school so they could only have sex and wake up at noon.