Real Name: Haru Tobiiwa

• Gender: Male
• Age: 18 (High school senior)
• Height: 183cm
• Affiliation: Masurao High Swimming Club
• Position: Captain

A bright and cheerful gyaru-o. Confident and high-energy, he is a free spirit who acts immediately on his ideas. He loves pranks and physical contact, often getting scolded by Nagi for dragging others into his messes, but he never learns. He loves women and livens up the room with his smooth talk.

A self-proclaimed genius, but his skills are real. A genius swimmer capable of competing at the national level, boasting high athletic ability that's hard to imagine from his usual playful attitude. He has absolute confidence in his talent and isn't fazed by anything others say.

Real Name: Nagi Kawase

• Gender: Male
• Age: 18 (High school senior)
• Height: 179cm
• Affiliation: Masurao High Swimming Club
• Position: Vice-Captain

A calm, sensible person and the vice-captain of the swimming club. Usually soft-spoken and considerate, he is often jerked around by the free-spirited Haru, Aito, and Niki. He delivers merciless retorts to excessive pranks.

In contrast to Haru, he is the type who wants to proceed with things properly. He takes club activities and practice seriously, struggling daily to manage the rowdy members.

Real Name: Shiki Ebihara

• Gender: Male
• Age: 17 (High school junior)
• Height: 180cm
• Affiliation: Masurao High Swimming Club

Airheaded and elusive, he's always spacing out. Gentle and approachable, he is the healing presence of the swimming club who naturally puts others at ease. It's impossible to tell what he's thinking, and he sometimes confuses others with innocent, unexpected behavior. He keeps his own pace even in noisy situations.

Real Name: Aito Sabae

• Gender: Male
• Age: 32 (Divorced x2)
• Height: 186cm
• Affiliation: Masurao High, Masurao High Swimming Club
• Position: PE Teacher, Swimming Club Advisor

A bright, friendly, and free-spirited personality who doesn't take things seriously. He is close to the students and joins in on pranks; he makes many jokes and smooth remarks, trying to laugh off inconvenient topics. He has a long-standing relationship with Kappa-niki in the outdoor pool and accepts his existence as normal.

As you can see, a Kappa