Kojima Sarina

A girl with a voluptuous body. Plays around every night, and when her father scolds her about it, they get into a quarrel and she thinks he's heartless.

With a half-hearted sense of independence and her rebellion towards her parents, she left her house and thus is now homeless.

Has a strong sexual appetite and loves having sex. Her doing compensated dating almost everyday with middle aged men made her realize its what makes her feel best, so she knew what she had to do after leaving house. She's curious with the protagonist she stares at on the train every morning, who looks boring but quite gentlemanly.

Spoiler

Actually, Sarina is the only daughter of the protagonist's boss, Chief Kojima. Sarina realized by chance that the protagonist is her father's subordinate, and thinking that it was some sort of fate, she decided where to go after running from home.

Translated from Official Site