Unbalance
English title: Sibling Secret: She's the Twisted Sister
Japanese title: アンバランス
Type: OVA
Episodes: 3
Source: Visual novel
Genres: Hentai
Studios: AT-2
Producers: Discovery
Duration: 30 min per ep
Rating: Rx - Hentai

The Hungry Bear is a restaurant where carnal appetites are satisfied to order. The waitress, Mika, has just uncovered the secret life of her late sister, a woman who would perform any sexual act, no matter how bizarre! But the secret's all in the sauce, and Mika vows to service her clientele's insatiable appetite for the exotic!

(Source: AniDB)