Mr. Heart

With a smile as bright as a sunbeam and a heart full of resilience, Go Sang Ha (Lee Se Jin) sprints through life. An orphan working multiple odd jobs—from delivering milk at dawn to cleaning a university gym—he finds his purest joy on the track, where he serves as a pacemaker for his school's running team. Sang Ha’s world orbits around the brooding marathon ace, Jin Won (Cheon Seung Ho), a record-breaking runner so focused on his next race that he barely acknowledges the cheerful boy who constantly cheers him on. When a twist of fate lands Sang Ha as Jin Won’s personal pacemaker, their dynamic shifts from distant admiration to forced proximity. Jin Won is prickly, sleep-deprived, and obsessed with winning, while Sang Ha is sunshine personified—determined to break through his idol’s frosty exterior with warm milk and relentless kindness. As they train together, their connection deepens into something tender and unspoken, but shadows loom. Sang Ha is hiding a crushing debt left by his late mother, and a group of aggressive loan sharks will do anything to collect—including forcing him to sabotage his own dreams. Can Sang Ha keep his promise to be Jin Won’s pacemaker while battling a threat that could tear them apart? *Mr. Heart* is a short, sweet Korean BL that fuses the thrill of the track with a soft-blooming romance. It’s a story about two runners finding their rhythm together—one learning to slow down, the other learning to trust—proving that the best races are run side by side.