Curate, connect, and discover
What if Atsushi knows sign language?? Like in the orphanage the kids would use it to communicate sometimes without the staff knowing, so even if Atsushi wasn't involved he gradually learned sign language to find out where to sneak food, good hiding spots if something happens, and how to get away easily if you do something. He knows how to sign fast too cause the kids would cut deals with Atsushi that if he used the fact that he was much scrawnier than the other kids to do something, then they would split something, mostly food though. So he can sign fast, fluently, and easily understand it even if it's rushed or unclear to most.