A girl eats an angel's halo by accident and starts birthing rainbow mushrooms. That's the entire promise, and the show commits to it with zero apology. The comedy lives in that gap between "this makes no sense" and "yes, we're doing this anyway," which is exactly where the best stupid anime lives.
Botan Ichige transfers to St. Asmaria All-Girl's School expecting a normal high school experience. What she finds instead is that the rumors are true: actual angels walk these halls. When she meets Un, a cheerful angel, things take an unexpected turn. A simple accident leads Un to offer Botan her halo as a snack, and Botan, caught off-guard, eats it. The consequences are immediate and bizarre. Botan's body begins producing colorful mushrooms on a regular basis, and she has no idea how to stop it. What should have been a straightforward day at school becomes a comedy of errors as Botan tries to hide her mushroom-spawning condition while navigating life among celestial beings. She scrambles to understand what the halo actually was and whether she can reverse its effects. This special thrives on absurdist humor and the fish-out-of-water scenario of a normal girl suddenly caught in the supernatural. It's lighthearted chaos perfect for viewers who enjoy silly premises and don't mind where the comedy goes.