After returning to Fuhren, Hajime heads off on a date with Shea, which comes to a sudden close when they stumble on a kidnapped merfolk girl.

Hajime's party makes their way back to a familiar location. Deep in the Labyrinth, a new foe threatens the lives of his classmates.

When Hajime's classmates are threatened by a demon mage to "join or die", it's up to him to rescue them -- whether they like his methods or not.