Shokkan Ingoku ~Torawareta Otori Sousakan Riru~

The protagonist unexpectedly gets transferred to a new department and encounters a younger, attractive female boss named Lilu. Initially feeling gloomy, the protagonist gradually develops a fondness for Lilu, who, despite her bold demeanor, occasionally reveals a cute side. However, Lilu's unusual task involves sacrificing her own body to lure monsters, engaging with them intimately, and extracting their energy to exterminate them. Recognized for her spiritual abilities, Lilu has special investigative authority from a certain organization. The protagonist, curious about why Lilu undertakes dangerous missions alone, discovers her motivation when witnessing her compromising situation with a monster. Despite Lilu's struggles, the protagonist, bound to a passive role, experiences a new and forbidden pleasure, creating a complex situation where they must confront hidden secrets.

[Translated from DLsite]