Joon-hyung's cousin and ersatz older brother, with a kind and gentle personality. A former athlete who becomes an obesity doctor due to an injury. He becomes Bok-joo's first love (without his realizing it) after he kindly lends her his umbrella on the street, even though at the time she is a complete stranger, and she enrolls in his obesity clinic so that she can meet him, although her need as a weightlifter is to put on weight rather than losing it. He treats Bok-joo like a younger sister and generally shows support to his brother's decision to like and date Bok-joo.