Im Yoona is Kai's girlfriend. But she was diagnosed with heart failure. She died in a young age. As for Kai, he locked his heart away. Meaning that he'll never love any other girl that he sees. But then...when those 3 years had passed...a girl who looked a lot like Yoona. Kai thinks he's just imagining stuff but...what if they're meant to be? Before Yoona died, she left a letter for her beloved cousin, Im Minji. What was the letter about? Will Kai move on and love Minji? *UNRXPECTED SMUT CHAPTERS*