Gosenzo-sama Banbanzai!

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," and claiming to be a granddaughter of Inumaru who's travelled back in time with a time machine to visit (and live with) her ancestors. Another character arrives later claiming to have a mission to stop such behaviour. Despite Tamiko's strong objection, Kinekuni and Inumaru welcome her to stay with them, the structure of a happy family has begun to collapse. (ANN & me)