Jeon Jungkook, a 17-years old boy, who just move to his boyfriend's house and attend the same college, has experience a heartbreaking break-up. Kim Taehyung, 20 years old, who is a friend of Jungkook's boyfriend, always by his side since the break-up. They fell in love by chance. After 3 months been in love, Taehyung's first love came back which he wasn't expected since she chose to study abroad. Taehyung and his first love actually never break up, he promised to her that he will wait for her no matter what but.... it's been 10 years. Taehyung has mixed feelings, he is a happy man when he's with his first love but he's already in a relationship with Jungkook. At the same time, Jungkook felt anxious and worried as he felt like he's losing Taehyung day by day... In the end, who will Taehyung choose?