バカだけどチンチンしゃぶるのだけはじょうずなちーちゃん

Based on the erotic game by OrcSoft. "Hey, Kou-chin. Sorry to bug you but, will you help me study?" It was a Saturday. There was still a month of summer vacation to go. Due to complicated family circumstances, Kouta - "Kou-chin" - who lives alone meet Chieri - "Chi-chan" - a classmate of Kouta's a...