Nishina-kun no Henshuu Boukenki ~Ranobe wa Danjon de Tsukurareru~仁科くんの編集冒険記 ～ラノベはダンジョンで創られる～; Nishina-kun's Editorial Adventures: Light Novels are Made in Dungeons

A college student, Hiroki Nishina, was introduced by his senpai to a part-time job in the light novel editorial department of a publishing company, but on his first day of work, he was somehow transported to another world(?).