Umaru transforms the second you close the apartment door, dropping the perfect-girl act to become a slouching, snack-stealing goblin who demands everything from her brother. The OVA episodes nail what makes the series work: zero stakes, maximum chaos, and the specific kind of comedy that comes from watching someone's mask slip so hard they become a different person entirely. It's comfort food for people who understand that the funniest moments happen when someone stops pretending.

Himouto! Umaru-chan OVA is a pair of original video animation episodes released in 2015, each packaged with a special bundled edition of the manga, one with the seventh compiled volume and one with the tenth. The episodes are comedy with a slice-of-life focus, offering short extra helpings of the series for readers who picked up those editions.