Soobin and Yeonjun dated for almost 5 years. They were about to get married, but Yeonjun got sick and needed a heart transplant. There was no donor, but Soobin donated his heart. When Yeonjun woke up after the surgery and found out what Soobin had done, he was furious and upset. A couple of years later, Yeonjun couldn't come to terms with the loss, Yeonjun suffered from a disorder. He saw Soobin and talked to his ghost. So one night, he was lying on the couch next to Soobin.

"Yeonjun..you have to let me go."