At Lake Yamanaka, bustling with a welcome camp for new members of the university sports club, a simple game to enhance teamwork is offered as a way to subsidize the camp fee. Seniors and juniors are invited to board the MM boat together! On one side of a single curtain, an adult game is played, and with a reverse magic mirror, everything is secretly filmed, including whether male members would end up engaging in silent sex if they get into the mood.