I've never made a game myself, just written a lot of things, so there's only so much I can say in response without just condescending about things I don't know. Please know that's not my intention, I'm just talking about scene construction.
My advice would be to look towards integrating the characters into 'downtime scenes'. You don't have to move straight from corrupting Tohka into corrupting Origami. You can have some scenes where the two settle down and interact with each other, with the protagonist, and with Shido and Kotori in the background.
This would be a good place to introduce the characters to people who haven't watched Date A Live, and generally to have scenes with the girls outside of direct corruption scenes. There's a lot of NTR games that have these kinds of scenes to them.
Scenes of the characters hanging out and paying more attention to the protagonist than to Shido, scenes of them doing sexual things behind Shido's back, that kind of thing. How does Tohka feel about the protagonist fucking Origami as well? How does Tohka feel about the whole 'family' thing now, and how does she view Shido? Does Shido ever want to go and do stuff with Tohka, but she's already made plans to go out with the protagonist and do stuff (and does that leave Shido feeling jealous, and how does Tohka feel about that- does she kind of get off on abandoning the guy who 'abandoned' her when she was feeling down)? Does Kotori ever try to invite Tohka to a movie night with them, but Tohka's already "busy" with the protagonist? How about Origami- would Shido ever try to rekindle that relationship with her, only for her to "turn him down" because she's with the protagonist already (fucking him while on the phone, for example)?
Etc.
I don't know your plot, I'm not the writer. At the end of the day, it's your game, so what you write is what you write and the readers really can just shut up and say thanks; you're the one putting in the effort to make the game, so criticism can only really be so fair. I just thought I'd talk a bit about why some netori fans might be a bit disappointed and decide to comment about it, that's all.