Takeko-san no Koibito(1990)

Houjou Takeko , age 27, is an ultra-competent secretarial manager at a large corporation. After work, she trades in her suit and horn-rimmed glasses for chic outfits and dances away at her favorite nightclub. Be it work or play, it seems Takeko is the perfect independent woman. But unbeknown to her colleagues, Takeko has a mysterious lover, Shi-chan, and through her eyes, we see all the pain, joy, uncertainty, and rewards of a relationship.