If you're saying that he's gonna sell porno of her, then I would have to doubt it. For once, the money has to be gathered from the classmates specifically. Second, I think he is too smart and complex to think of a plan like such.
I was thinking about next chapter all day, and I came up with a few theories. Maybe Yuuichi guilt-tripped Kokorogi into selling naked photos of her to his classmates or maybe he's gonna try to create a school scandal using Kokorogi. Anyway these are just some of my theories, but what I'm worried about the most is whether or not Yuuichi doing this to save Shibe because they're friends or just to win game 4 and crush the admins!
I feel like the school scandal theory is borderline very probable. But I feel like Yuuichi might be getting drunk on power and just really enjoys crushing the admins.
Why not collecting the money and exchange it with the classmates ones? It's said that it needs to be the money of those guys, so this wouldn't break the rule right?
I think he's going to use the photos as some kind of threat towards the classmates, Kokorogi isn't hated by the class as I've understood and I believe Yuuichi is gonna use that against them. Something in the style of this; sending the photos to the class with something like "if you don't turn in the money Kokorogi is gonna suffer a terrible fate (sex, rape etc) knowing this I don't think the class will be able to turn their heads the other way and in that way they will submit and turn in the money. But I'm not sure, anything can happen!)
Wow I really like your theory about the next chapter a lot, and thinking about it again that theory could possibly happen giving Yuuichi's sadistic side!
So your theory was almost correct :D
I think we all know what's gonna happen in the next chapter, here's a hint "sex sells"!