Hentai kazoku: Aniki no yomesan

In this 1984 Japanese pink film, Kaoru Kaze plays Yuriko, the new bride of Kōichi Mamiya (Shirō Shimomoto), who brings a sexually voracious partner into the family. Meanwhile, younger brother Kazuo (Kei Shuto) sees Yuriko as a source of sexual release, while sister Akiko (Miki Yamaji) secretly works in a soapland. The family's middle-class dynamics are disrupted by Yuriko's arrival, and tensions rise as the husband, Shukichi (Ren Osugi), lusts after a bar proprietress.