When Yuri and Marimo realize they're gaining weight, they decide to go on a diet. The naturally slim Kanae offers to coach them, but her advice is shaky at best. Will the girls be able to lose weight?

"Summer vacation is almost over," Kanae remarks during the introduction. Yuri snaps back precisely, "This anime's seasons are totally random." And that anime, Tekyu, is about to start again! Yahoooo!!!!

Marimo and her friends are trapped on an alien planet when their spaceship breaks down. While searching for the rubber band they need to repair their ship's engine, they come across a strange domed structure. When they open the door, they find a shocking surprise waiting for them.