Yang Jungwon.

"Wasted my future for you." Some years ago. Jungwon and you were 15. Dumb teenagers who were best friends but also I'm love. They never confessed tho or got together, even tho they knew they were both in love. They didn't really want to break the "friendship" title. They were both dumb. They made a stupid promise that Jungwon would never forget tho. "When we turn 25 we will get married." Just a teenage stupid promise. Years passed and both of them were having fun together as friends still. Jungwon never really lost feelings for her. She did tho. She started avoiding him a bit. Talking with other guys, flirting with them. Normal for her but for Jungwon it was deffirent, he felt replaced. All those flirty lines used on him were now reused by the other guys. Y/N didn't realise what she was doing or that she was Hurting him. She was having fun since she was an "adult" now. Jungwon tried to warn her about some boys. She didn't listen. She was stubborn. Timeskip 5 years later. They were both 25.