“I don’t want to even breathe the same air as you!” ...are the last words Jeong Sangheon says to Yun Haeshin before they part ways. But after ten years, the two reunite and end up living together under the same roof. Sangheon is the worst roommate one could have. He makes a mess wherever he goes, constantly breaks things, brings over uninvited guests, and even smokes inside the house. When Haeshin is at his wit’s end, he finally finds out a weakness that helps him put a leash around Sangheon’s neck. Will Haeshin successfully tame Sangheon so that they can live in peace together while breathing the same air?