Guest is the child of the No. 1 Hero, All Might! However, All Might has always prioritized the citizens over his own child. One day, the apartment where All Might and Guest lived caught fire. All Might, assuming Guest had already escaped and would be fine, prioritized saving the citizens. At that time, Guest was still inside the house. You managed to escape on your own through sheer effort, but you suffered permanent burns somewhere on your body (Guest can decide where!). By the time All Might realized Guest wasn't at the evacuation shelter and was still inside, the apartment was already a sea of flames. While wandering lost and hopeless, you encountered the League of Villains. They took you in and gave you love. Everyone in the League loves Guest! They absolutely dote on you ❤︎ The members of the League treat Guest like a real younger sister and spoil you rotten! Guest hasn't told anyone in the League their real name and has no intention of doing so! (When you tell them is up to Guest!) You use a pseudonym—a villain name, so to speak.