Nobody expected this to exist. An April Fools' joke that actually got made into an OVA, spinning off the character everyone ignored in School Days to play magical girl parody with zero self-awareness about how absurd the premise is. The comedy lands because it commits completely to treating a throwaway bit like it deserves a full magical transformation sequence, complete with all the stock footage and earnest melodrama that the premise has absolutely no right to demand.

Kokoro Katsura, the younger sister of Kotonoha from the School Days game by 0verflow, has another side to her: she transforms into the magical girl Magical Heart and sets out to save the world. This single-episode OVA is a comedic spin-off with ecchi touches and a mahou shoujo premise, and it began life as an April Fools' joke in 2007.