Nakamura Ami: Onegai yogoshite (2003)

Raika, an office worker, has multiple boyfriends and would see a different man depending on the day of the week; the men themselves are aware of and accept this arrangement. One day, while Raika is feeling lonely after being dumped by Okubo—her "Wednesday boyfriend"—her older sister Akio appears. The next morning, the two sisters set out together, but Akio keep veering off onto different paths. As Raika struggles to keep up, she's approached by a scout for a hostess club—who turned out to be Shunsuke, a former high school classmate...