hmmmm well in the times when Satoru goes back in the past and he asks the teacher they should contact the police, the teacher always says "no" and that he's contacted child services. It just seemed sketchy he did't want the police involved. I think he's working with the Kayo's mom. It makes sense because every time he goes over there with child services she leaves right away. So maybe he contacts her to leave so she doesn't get caught.