OVA 1 of list that came with the PlayStation 2 game "School Days L×H"

Makoto, Sekai, Kotonoha, and many other classmates all go to a hot springs hotel to relax, where they discuss what their plans are for the upcoming Valentine's Day. When the day actually comes, half a dozen girls fight over who gets to give chocolate to Makoto.

(Source: ANN)

OVA 2 of list: Originally an April's Fool in 2007, this one episode OVA is a spin-off of the School Days game by 0verflow, and shows Kokoro Katsura, the little sister of one of the main characters, from her other side. A mahou shoujo out to save the world, or something like that.

(Source: AniDB)