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

ENJOYING YOURSELF IS HARD WORK!Iffole's annual Centennial Festival is right around the corner, and Alina is hell-bent on indulging in the food and fun this year instead of working overtime like she did the last two festivals. But just a few days before the event kicks off, her aspirations are jeopardized when a massive group of adventurers swarm Iffole Counter! It turns out they've all been tricked into believing that anyone who finds and clears a secret quest will get a powerful Dia kill. So what's a girl to do? Simple -- give the creator of that baseless rumor a beatdown!