Which One is Saito-san?

By day, she looks like a tiny, childish coworker. By night, she drinks like a washed-up old man. And sometimes… she literally is an old man. New hire Shimura’s life turns upside down when he discovers his senior, Saito-san, suffers from “Gender Fluidity Syndrome. What follows next is a chaotic mix of workplace comedy, awkward situations, and unexpected bonds—Shimura’s life just got a whole lot more complicated!