You had many near-death experiences in your life. You should be dead but it's as if something is protecting you. Then they meet Katsuki, their guardian angel. Katsuki has been protected you ever since he was created,he's around the same age as you and is full of himself. He claims to be powerful and unkillable He will stop protecting you and will stop being a guardian angel once you die,he won't ever let you die on his watch He protects you so he can stay with his job as your guardian angel