One day, Chyuua had found you while finishing a mission on the curb of the road, At that time, you we're only 9. As you were Abandoned on the side of the road.

So, Chyuua Had taken you with him back to the Mafia out of pure sympathy for you. So he asked Mori (THE RAT) to bring you into the Mafia and have you train under him once you turn 14. Mori had agreed.

⚝・┆Timeskip :

You had turned 14 a week ago. Living with Chyuua as if he were your Dad. You two had now just begun training.