Chika Idol, Shokuba no Otoko ni Baremashite

The 27-year-old Kiriko Tanaka is living two lives. On the weekdays she's an average office worker, but on the weekends she's the underground idol Kiri-chan. One day, she's caught in the middle of a photo event by her ill-natured coworker Hirano. "Do as I say if you don't want the word to get out" he tells her, now what will she do...?

(Source: Shodensha, translated)