Yamasugi enrolls in an elite swimming school dreaming of one day joining a water rescue team. But there’s one big problem—she’s such a muscle fanatic that she can’t focus on practice at all! Then one day, she accidentally discovers the embarrassing secret of Kaiko-kun, the swim team’s ace who always wears a rash guard and never lets anyone see his skin…!? A heart-racing school rom-com of muscles, secrets, and first love begins!