Gosenzosama Banbanzai! (1989) IMDb
Oshii Mamoru (writer-director).
A modern family in an apartment complex is visited by a young woman who claims to be a time traveller and the granddaughter of the (current) young son. He falls in love with her and elopes, dooming the family.
OVA series. Arthouse experiment with music by Kawai Kenji, and sound direction by Chiba Shigeru! Some impressive animation, some nicely played conversations (Furukawa Toshio, who played Moroboshi Ataru, is the lecherous son Inumaru), some humorously blatant use of logos for Coke and Kodak, and enjoyable stylings throughout, including the “obligatory” Oshii tachigui scene in episode 6. The endless digressions are hard to follow and not very profound or entertaining.