Prologue.

5 years ago, at the time the fire that almost burnt down the whole city took place, a strange figure approached (Y/N) who was going to see her childhood friend Kotori at that moment.

"If you go save her, you'll die. But I can give you the power to survive those flames"

That's what convinced him to take that weird object, and rush to help his friend, not caring about anything else than her safety. That's were it all started...