Episode 10: The Circumstances of Wakasa's Friends: Maki Edition
Tatsumi rescues a river snail from a pair of young boys. The snail turns out to be Maki, another of Wakasa's friends. Maki is negative, self-deprecating, and careless, but impresses Tatsumi by cleaning the bathtub.
Tatsumi is a high school boy who lives by himself. One day, a devastatingly handsome merman named Wakasa moves into the bathtub in Tatsumi's home. Wakasa is a bit self-centered but cute, while Tatsumi is cool but a busybody.