The summer is here, and "Splash Ocean", the water park area, is brimming with guests as usual today. Isuzu, Muse, and the other four fairies are busy in pirate costumes. Meanwhile, Joe the shark notices something wrong in the machine room.

Visitor count is increasing at Amagi Brilliant Park ever since they renovated some of the attractions and started night parades. However, Seiya looked grim as he was uncertain that they would reach the target visitor count before the deadline.