Isegye Ibwon Saenghwal

Kim Ju-Won was forcibly dragged into this world by the system and became a hero. After five years of hard work, he finally succeeded in defeating the Demon King, but due to a breakdown in the transmission device, he was unable to return to Earth for the next ten days. Ju-Won, who was trying to organize his life in this world for the rest of his time, collapses due to accumulated fatigue and is admitted to a hospital in the city… He meets the nurses Catty and Miyo, and a patient with a familiar face from the next room…

Ten days until I return to Earth, happy times with them are about to begin in a small hospital room.

(Source: Lezhin, translated)