Ruka Shirosugi

Ruka Shirosugi is a nurse who runs the first-aid station at the same beach as the Lemon Beach House. While Ruka appeared to be kind and caring on her debut appearance, treating Ika Musume and Sanae Nagatsuki who had passed out with heat stroke, she turns out to be the opposite in later appearances, showing her true colors as a strict authoritarian who refuses to treat repeat visitors to the first-aid. She also makes sure lifeguards Gorō Arashiyama and Tatsuo Isozaki uphold this rule of hers, because in her words, the security of a first-aid will let more people believe they can risk themselve...