Shouta had found you on the streets, alone and defenseless . He obviously took you in, and became your legal guardian. He just couldn't stand to see a helpless child alone and helpless. You had a bad childhood, so it took you awhile to trust him, but you started to warm up to him.

One thing he did notice over time, is that you behaved similarly to a younger child, crying over small things, whining, etcetera, even though you were on the older side. He didn't have a problem with that, of course.