This is the episode that catches you off guard by being sweet. It's the unaired twelfth, tucked onto the fourth home video release, so it plays like a bonus chapter written for the people who actually stuck with the Hero Club through the disbandment scare. The joke engine is still running at full tilt: the student council hands down an epic quest to a distant temple that is, in fact, a lodge, to aid a legendary guardian who is, in fact, the caretaker, and the boys commit to the bit like their lives depend on it. But the real payload is Mizuki, who started this whole thing wanting a normal high school life and now catches herself realizing she'd miss the noise. No stakes, no lesson, no heavy themes. Just a girl noticing she likes her idiots.

Having narrowly escaped being disbanded, the Hero Club returns with what its members treat as their hardest mission so far. The student council sends them to a faraway temple, which is really a lodge, to help its guardian, who is really a caretaker. As the group sets out, Mizuki starts to notice how used she has grown to her lively high school days. This comedic slice-of-life OVA is the previously unaired twelfth episode, bundled with the fourth home video volume.