A-Be-Ko-Be

Original title: あ・べ・こ・べ セクシーボディ姉妹のHなヒミツ

Aoi and Akari are two sisters and complete opposites in terms of personality and lifestyle. But when a mysterious earthquake rocks them, they end up tumbling down a bank and their bodies and minds are swapped! The two decide to live their lives as each other and to hide this secret but...