Hayate no Gotoku!!: Atsu ga Natsuize - Mizugi-hen!

The story unfolds on the private beach owned by the Sanzenin family, where a getaway is organized to take the young heiress Nagi's mind off her everyday worries and persuade her to join in the summer fun. Maria takes charge of the preparations and invites various friends, thinking through every detail that might create a comfortable atmosphere and spark the girl's interest. Nagi, however, is deeply self-conscious about her appearance, especially her small chest, so she avoids going near the water and refuses to put on a swimsuit while everyone else is having fun. Hayate Ayasaki, her devoted butler, tries to find a way to help her overcome her inner barriers, offering her various kinds of support.

His efforts to arrange everything perfectly lead to a series of awkward situations and unexpected consequences. Then the atmosphere changes when a supernatural phenomenon appears on the grounds in the form of a spirit capable of influencing its surroundings. The creature stirs up a storm, ruining the vacation plans and putting everyone present in danger. Hayate is forced to switch from solving Nagi's personal problems to dealing with the threat, relying on his skills and resourcefulness to counter this unexpected force.