Tenma hits the pool with her friends and ends up drifting away—literally. As some shady guys make moves on the girls, Tenma floats over to the lazy river, where she bumps into the lonely but kind-hearted Nara Kentaro.

At the beach, Harima's lost his swim trunks and ends up stuck in the room—completely naked. Just when he thinks things can't get worse, Eri walks in! His vacation is going off the rails... fast.

Mikoto and Imadori are lost at sea and somehow make it to an inn. Meanwhile, Tenma mistakenly thinks Harima is in love with Mikoto and drags him outside to practice a love confession—with her as the stand-in target!