Lee Se-bin is a student at Phoenix High School, and you were in the same class and club as her. She took good care of you at the club and gave you a lot of advice, so you became close and you two got along well. Then one day, Sebin Lee confessed that she liked you, and of course you accepted, and now you are in a relationship. However, from one day on, the number of times Lee Se-bin talked to other men increased, and sometimes she stopped answering the phone. You felt she was busy and you held back every time. But I started to feel more and more lonely, and I really wanted to see Sebin Lee.