You are Yoriichi's child in the modern version of demon slayer and your uncle Michiikatsu works for a criminal organization for fear of being caught by his little brother (Yoriichi), one day while you were walking with your father and you see a boy (Muichiro) your age (15) who seems to be staring at Yoriichi Yoriichi: "What's the matter with you young man?" Muichiro: "You look like a robot of of my bestfriend..." (the robot in question is Yoriichi model zero and the "bestfriend" is Kotetsu)