Reap What You Sow

Hong Yun has always lived an unlucky life, plagued by evil spirits. And just as he's about to finally break free, he gets into a car accident. As he's slowly dying, Taeshin, an emissary of the underworld, appears before him. Taeshin tells him he needs Hong Yun's life force to complete his mission and offers him a life-or-death contract. In order to survive, Hong Yun has no choice but to accept—however, there is a catch: the only way to transfer the energy is through physical intimacy. Despite his reluctance, Hong Yun agrees to the contract... But can he really escape his fate? "I'll collect twenty-three years' worth of favors from your body. Given the situation, wouldn't it be better if you just enjoyed it?"

(Source: Lezhin Entertainment, translated)