Ko was a boy who adored oranges more than anything in the world-but not just any oranges. They had to be from the tree next door. No other oranges tasted so good or made him as happy. Fragrant, sweet, delicious-everything about those homegrown oranges, Ko loved completely. Except for one thing: the orange tree's true owner. That boy, the one with the cool name jut the same as Ko's. Everyone called him "Ko Two," as was customary when two people shared the same name. And so, Ko naturally became "Ko One." But the similarity ended with their names. Their personalities were complete opposites-as if heaven had sent a masterful celestial being to punish a mischievous little orange demon. As the story of the two Kos unfolded, they grew-both in body and in the feelings quietly forming in their hearts.

The story of two ugly ducklings drifting in the vast ocean. "Maan," a young boy who has just moved in with relatives after his grandmother passed away, must transfer schools to start a new life. He sincerely hopes to make the most of his high school years and is determined to make at least one friend in these two years. He has been lonely and isolated for far too long. He just wants to fulfill his grandmother's last wish: To have a friend. Just one friend, that's all. Because until now, the HIV he carries has been the biggest obstacle to his social life as a child. But before school even starts, he meets "Tharn," a neighbor who lives in the same alley and seems to be a classmate as well. "Hi, my name is-" "I don't want to get to know you." "Step back." Tharn doesn't even look at him, coldly rejecting him. All Maan sees is Tharn's back as he walks away. Maan has just gotten to know this new friend. He hears that Tharn was once a provincial-level swimmer, but something happened that made him step away from it. He abandoned that dream and never thought of going back. It's a pity that some kinds of intelligence cannot naturally manifest in youth. How will the story of these two young boys, both carrying emotional wounds, continue? The time of blossoming has arrived. The question is.. will they use this time to learn, grow, and move forward happily?

When Aii and Koon are heartbroken by the same person, the two take comfort in each other and find they have a lot in common. Given all the time they're spending together, to make things easier, they agree to live together. As their closeness grows, Koon's bandmates attempt to persuade Koon to act on what they sense goes beyond friendship. Afraid of losing what they have but also of losing Aii if he can't return his feelings, Koon proposes a twenty-one day experiment to see if Aii can make him fall for him.