While walking by the river, high school student Tatsumi spots a beautiful man collapsed on the ground.

Just having a merman live in his home is difficult enough for Tatsumi, but another major problem arises.

One weekend morning as Tatsumi heads to the bathroom with breakfast, he hears lively voices coming from inside.

Tatsumi informs Wakasa and Takasu of a rumor about a ghost appearing in a nearby park; then, behind Tatsumi, a mysterious white object appears.

Wakasa has become obsessed with the fantasy of taking a bubble bath, but doesn't understand when Tatsumi pulls him out of the tub.