Arata Kasuga decides to become a mage in order to save his lost cousin.

While doing research, Arata and three of his classmates get locked inside a sealed room. With no exit to be found, the group find themselves in desperate need of the bathroom.

The group spend some time at the beach, where they enjoy the hot springs. Arata discovers that he must choose his Theme to prevent disaster.

When a power leaks from beneath the school, Arata and the gang go down into the labyrinth to save the school from the collapse phenomenon.

When a ghost suddenly appears in the library, Arata and the gang go to investigate and are transported to the Eternal Library.

In the midst of another breakdown, the group discover that a member of the Trinity Seven is the source of the chaos.