Okay, so what if Denji had never learned how to swim?

It's not like it was a dire skill that Denji NEEDED to learn. So he hadn't put any effort into learning it. Who cares? It's not a loss.

Now he's reconsidering. It's dark, and he's alone at the school campus. Well, other than...

Denji can't help the heat that rises to his face. Shit, why hadn't he ever put effort in learning how to swim?

He doesn't give himself twice to reconsider. He's in his boxers, staring down at the pool.