I thought of a feature for your game that I think would be a great add for fmg fans.
A continuously updating size chart. That you can view from the start of the game to the end. Show the relative sizes of the characters compared to one another. Much like the UI artwork that you update whenever Gina goes to train, this is a great thing to add so we can keep track of the scale of everything. For example I can never tell how big Gina is depending on who she is next to. Akari looks absolutely massive next to her, but I don't think the difference is as big
I put a link to an example of an Imgur height chart. Artwork is by Robolord who primarily does FMG but occasionally also does some male muscle growth.