Suki shakazoku: Vibe de nagusame (2001)

The Miyoshi family is currently living apart from the father, who is on a solo overseas assignment in Thailand. Their son, Tsubaki, is enjoying juggling relationships with two different women. Then, one day, his twin sister Sakura—who had been studying in the United States—decides to return home for a visit, bringing along her foreign boyfriend. Their mother, Reiko, finds herself fantasizing about having sex with a white man...