My Fox-Spirit Wife

The protagonist unexpectedly catches the eye of a fox immortal and strikes a deal with her. Along the way, the fox immortal helps him win over his beloved, thrive in the workplace, and rise through the political ranks, while ensuring that the villains get the punishment they deserve. In return, the protagonist helps the fox immortal search for the life-preserving salve, embarking on a winding, strange journey full of twists and turns.