Gosenzo-sama Banbanzai!
English title: Long Life To The Ancestors
Japanese title: 御先祖様万々歳!
Type: OVA
Episodes: 6
Source: Original
Genres: Avant Garde, Comedy, Drama, Sci-Fi
Studios: Pierrot
Duration: 28 min per ep
Rating: R - 17+ (violence & profanity)

The Yomota family is small and typical: father Kinekuni (42), mother Tamiko (38), and son Inumaru (17). One day, a beautiful girl appears at their front door, calling herself "Maroko Yomota," granddaughter of Inumaru who travels back in time with a time machine to visit her ancestors. Even with Tamiko's strong objection, Kinekuni and Inumaru welcome her to stay with them, and the structure of a happy family has begun to collapse.

(Source: ANN)