Unable to find the company commander Ishizuka's house, Nagano stays at Senju's parents' inn. On the other hand, Sakuma, who is attracted to the mysterious girl Mizuho, decides to invite Mizuho to the fireworks display as she is teased by her surroundings. She asks her childhood friend Azusa, who is good at handling gunpowder, to make her own original fireworks, but...