I May Be a Guild Receptionist, but I'll Solo Any Boss to Clock Out on Time, Vol. 2 (manga) — Mato Kousaka

The boss found out about Alina's side hustle?!

Seeing Glen Garia, the highest authority of the Adventurers Guild, standing in front of her reception desk is terrifying enough for poor Alina, and what he has to say is no relief: His skill, Sigurth Chronos, let him look into the past and glimpse beneath the hood of the “Executioner,” Alina's alter ego! Glen invites -- or rather, orders -- her to guild headquarters and offers her a way out. If she wants to keep her comfy job and avoid getting press-ganged into the Silver Sword party, all she has to do is defeat the Guildmaster himself!