>>530177017
Couple of them receive fanart
Mostly otogi and Niko

Character popularity depends a lot on you being rollable though, being rollable and having momotalk scenes with sensei will shoot your popularity up a lot usually. If you arent rollable you usually end up in forgotten tier with the other forgotten characters. Look at how much being rollable upgraded the Shuppokaki's popularity in the end, Nozomi used to be a lot less popular.