R:
It's funny you mention the milf/big sister archetype in harem manga. The issue I've always had with them is that they tended to sink into the background for the most part. They either spend their time smoking/drinking by themselves or being presented as mother figures without actually doing anything responsible (or in some cases, being anything but responsible in how they play with the main character's feelings).
All that aside, our main challenge with that possibility is figuring out why Ronald would create such a thing in the first place if he's truly looking for a meaningful relationship.
Personally, I was playing with the idea of a girl old enough to adopt an authority role while still being considered a peer. It seemed better to fit the demands of Ronald's wish for girlfriend candidates and the whole competition angle. I couldn't really imagine a milf competing with teenagers for another teen's affections, at least, not in any healthy sense.
That said, an upperclassman tutor girl just seemed a little bland when compared to someone like Dalia, so I was trying to come up with something to make her personality fun without rehashing her P and F quirks.
P:
For Jon, that's why I kept the whole rock/grandfather mystery in the game, as it gave his character more flavor. I imagined him having more important things to worry about than seducing Ronald, which could mean a reversal of roles with Ronald working to seduce Jon.
For myself, I think of both Ronald and Jon playing out their own stories parallel to each other. Ronald's quest for a girlfriend will, of course, affect Jon's quest for answers, and vice versa. How? Well, that's the fun part!
Possible aspects of Jon based on other people's portrayals: Friendly, mysterious, loyal, responsible, contemplative, down-to-earth, maybe outdoorsy, maybe gamer, maybe tech/inventor guy, maybe magical, charitable, helpful, maybe a rebel, maybe a romantic/realist/idealist, (as a girl) tomboy?, cheerleader?, Goth to match Zoe?, reader/writer, artist, actor
