So we all know how due to having a rough time in sixth grade Shouya was really antisocial until having finally found Nishimiya again.
This led to him unexpectedly having a friendship with Nagatsuka, someone who is always willing to help him out and to also push Shouya into things he doesn’t want to do, which works out for both of them in the end.
That leads to him going with Nishimiya alone to find their old classmate Sahara, due to Nagatsuka and Yuzuru bailing out of the trip at the last minute.
Point is, I’ve noticed him slowly changing his personality the more he becomes friends with these people. He’s becoming a bit more sociable and outgoing. With just a little more pushing from everyone else he might get back to his old self! That’s character development right there!
It's An Anime Thing 