So I've downloaded this on android recently and gone down the PRG route first only to be bombarded with errors about side character portraits. After a bit of looking through the files and staring at the errors, I think I've found the issue to be that joiplay is looking for slightly different folder than what exists, entirely caused by a difference in capital letters.

The only side characters I've encountered to not have an error show up are the RM, the faculty and strangely enough Chiyo, Chibuki and Ryoko.

Though these are all thoughts from someone who knows nothing about game Dev so I might be wrong but I figured it was worth bringing up.

Oh and bravo team, I was not expecting to get invested in a game that I just wanted to see a couple breasts and bellies grow but you managed it. I think I'm still kind of early on at PRG037 but I'm enjoying reading through quite a bit.

Oh I should mention that before I made this post I did try renaming the files to be capitalised but each one I tried said that there was already a folder of that name

Thanks for bringing it to our attention. We're looking into the issue. It seems to be related to how the sizes are assigned to the side characters, which is different than the main characters. We hope to have a fix for the next update but we don't know if that will cause other bugs at this time. 

Glad you are enjoying the story!