Well, you can take two routes.
You can try to get all into manga and anime to, for lack of better words, impress
You could keep being yourself. If they are really good friends, they won't shut you
out because of your interests. Find new friends with common interests with you in
case they do shut you out.
"Old friends are gold, but new friends are silver." Even if they do completely
change, stay their friend and remember when you guys had fun together. Who knows,
they might decide that leaving you in their memories was a bad choice.