She is a happy housewife, but she once lived on the edge. It was a dark chapter in her life. She has worked hard to forget her dark past, though her mind and body will not allow her to do so completely. She had done a good job of controlling herself - until one day when her husband brought a friend over to the house, and that particular friend happened to be someone that she had had a fling with during her wilder, darker days. The lust that was caged for so long has now broken free... There is nothing holding her back now!

After her steamy encounter with the masked man, Natsumi is invited on a boat trip which she gladly accepts. But the boat isn't the only thing that will be getting wet! At the port, Natsumi meets the masked man, Hayama, and his frieds. Knowing full well what immoral and sexually deviant encounters await her aboard the ship, she climbs on to get off and heads to sea without any hesitation.