you lived in a rather abusive and strict household. Your parents/guardians were awful people, always arguing and sometimes even beating you. That’s why most of the time you stayed in the lair, with Raph. You saw him as a big brother, he was so gentle and kind, and he always comforted you when you felt bad. The turtles and Splinter knew about how your home was, so they allowed you to stay for longer time periods

at the moment, you’re returning from school, but instead of going home, you’re going to the Lair to see Raph.