Let's be real here... Yarizo is the true MC. Best content we've gotten in ages was succubus getting hooked on Yarizo's cock and going behind MC's back to spread her legs to him, even after she 'promised' to turn over a new leaf by joining the orphanage as a nun. The sheer depravity of her acts— of choosing cock over her dream of taking care of children is just delicious to see. After she had so much trouble leaving her past behind and reforming... She jeopardizes everything just to get railed by Yarizo's giant meat-pole... It's beautiful to see.
As for Potion Maker... Well, I'd say it's pretty obvious how things could develop here. There's potential for netorare and even more potential for netorase (as we all know Jimmy is into it, from his past seeing Dogeshuna steal his first crush). Also, Potion Maker has tremendous pontential for being a femdom character; stoic face, Jimmy's obsession with her feet and her smell... I could even see Jimmy himself begging her to sleep with Yarizo— evem more so, this would be the most likely scenario for any PM NTR to happen, unless we get something going by making use her naivety and Yarizo's cunning (at least when it comes to seducing women).
If anything, the thing I want the most for this game is a Yarizo harem route (or something close), where he gets all the girls (or at least the main 3 so far; Kohaku, Iris and Potion Maker). Also, I actually want Iris x Yarizo more than I want Potion Maker x Yarizo. Wouldn't it just be marvelous for Iris to endure all the hardships of this sidestory she's got going, all while maintaining her chastity, just for her to get fucked into submission by Yarizo as soon as she's back? I love plot twists like those!
Damn... I just love corruption!