Hiruneburu.

Synopsis

During class, the "nap lover" Niiya Isomura is constantly sleeping. His favorite pastime during lunch break is to monopolize the unused boys' swimming club room for his nap! However, the talented and beautiful student council president, Remu Naruko, suddenly bursts in and declares the start of a new club: the "Napping Club!" Remu wants to prove the improvement in academic efficiency from afternoon napping, while Niiya, who wants to enjoy his peaceful naps alone, reluctantly gets caught up in it. Will he be able to resist... or not?! (Source: Hero's, translated)

Anime adaptations