Manatsu and her friends plan a trip to the city's aquarium to see a new dolphin attraction. On the day of the trip, the dolphin attraction's wait time is too long, forcing the girls to look at other aquatic displays to pass the time. Despite the plan to wait for the crowds to thin, the dolphin attraction is still too long. Meanwhile, Manatsu and the others notice that the people visiting the aquarium have become lethargic. Deciding to investigate the matter, the girls book a night tour to allow Laura to scout for any suspicious activity. Laura runs into Numeri and chases her into the dolphin attraction when Manatsu and the others arrive...