College student Hayato Ookami lives next door to Ginki Shiroki, a teaching assistant for one of his classes, who always seems to wear a stern expression. Their already tense relationship only worsens when Shiroki chastises Ookami about being too noisy at night. But when Shiroki's cat escapes into Ookami's unit, he walks in there to a surprising sight: Ookami has wolf ears and a tail, and the full moon has left him with an overabundance of sexual energy.

Now that Shiroki is privy to his secret, Ookami starts to forge an unlikely bond with him. However, Ookami remains concerned that his animal side will eventually get in the way of their relationship.