Ooida Kaoru

She is a high-flying elite secretary. While she is competent at her job, she never shows her weaknesses to anyone and stress builds up.

However, by having wild sex with an aphrodisiac, she discovers a new side of herself and...?

Spoiler

She has had an affair with Koyasu Takahito and mentions that he is a big pervert, not all that different from the protagonist.