"No matter how much you regret it, Hyung, I won't let you go this time." Kwak Chieon, having just turned twenty, surprises the adults by declaring he won't go to college. In truth, he has a much clearer goal: to win over the older brother next door, Hyun Woojoong, who he believes is his destiny! Frustratingly, Woojoong, whom Chieon has watched since childhood, is playful and constantly cycles through casual relationships. Despite this, he dotes on Chieon, confusing him with displays of possessiveness. Now a confident adult, Chieon decides it's time to put his plan into motion. He steels his heart and pursues Woojoong with unwavering devotion...?!