I think it was the adopted mom who framed the mc and wants to kill him rather. He knows that the mother is a killer thus, a way of silencing him is to do that hmmm. Or the ml is just a 100% asshole.
I dont know about plot similarity but here are some guideverse stories: Dear 00. Guiding Hazard, B-Class Guide, The Ordinary lifestyle of a universal guide, Conditions of a Guide, Over the Paradise, How that Guide is loved ヾ(❀╹◡╹)ノ~hope this helps!
: "Don't tell anyone"
: "Takes a picture with everyone (and a famous actor too)"
Yup, just to keep the story going