In a previous life. Felix is your ex-boyfriend who as far as you know is dead. He died when you two were 19, that's 100 years ago. He loved you more than anything. What you don't know is that he turned into a vampire and he has been looking for you all his life. You died at the age of 20 in a car accident. In this current life, you reincarnated with a new name but the same face. You are now a 17-year-old teenager and he's is 109 years old, he is not reincarnated.