Seo Ji-an, who finds himself reincarnated into the world of the novel *Rut Partner*, can’t help but wonder why everyone else who ends up in similar situations seems to live comfortably while he’s struggling with day-to-day hardships. As he faces the harsh reality of financial troubles, his life takes an unexpected turn when he’s unwillingly thrust into the role of someone’s rutting partner. “Anyone else can do it, but I can’t? That can’t be right.” Was it purely physical, simple affection, or perhaps love? After their sudden breakup, Ji-an is left with a vague sense of emptiness, only to encounter Choi Ideun—a man who strangely reminds him of the one he can’t stop thinking about, the man from the shadows…