I know this isn't really like what others are saying but i feel i should bring it up. I love this game quite a bit and enjoy it. It's honestly the best Naruto game of this type made period. And that's just a sad fact despite how many have tried. So i want to offer something/question something.
Have you ever considered offering players a choice at some point? Namely that, a player can choose the normal path the game is on, being this corruption and mind control path, or a more romance/mind influencing path. The reason i bring it up is, as you have written the story and interactions with each of the girls, there is actually some logic to this.
Before the main character uses the Jutsu on each one of the girls, with their interactions before it happens, each girl clearly was shown to like the main character and had a degree of trust twords them.It would not be hard to build upon that in my opinion by simply including an option. A player can choose to use the full jutsu on them to mind control them as is normal and have things play out as they do. But a player if they don't entirely like or want that kind of thing can choose to use it in a way that instead influences their minds to have feelings twords the player.
There can still be a corruption/training aspect as they are still messing with the girl's minds but the core diffrence would be that the girls would not be fully controlled and instead be romantically interested in the player character and it can have their minds toyed with a bit to be ok and open to more sexual things much more quickly than normal.
As well, this doesn't necessarily mean entirely new scenes need to be drawn and animated. The normal ones can be reused just with sligthly diffrent expressions of course and dialogue. As well the context for some of the scenes can be simply explained as the player using the jutsu to make the girl open up to a kink or fetish they have but never have acted on.
Sakura had fantasies of being tied up and bound.
Ino likes having her ass played with.
Hinata has wanted someone to watch her toy with herself.
And so on.
As for why you would be able to have multiple girls at once without one being upset by it, equally simple,one of the things influenced by the jutsu is that the girls don't notice or care if the player does sutff with other girls. Allowing the story to be rouphly the same.
Some extra scenes could in theory be added like groping or the like but that's besides the point. This would still allow the character moviations to be the same, still allow hte same story for the most part and similar gameplay, but also allows new scenes or to reuse older ones but with slight alterations and new context and it makes it so the girls wouldn't need to be controlled for them to be around the player as they would be interested(as far as they know) in him of their own free will.
Sorry if this is long but i wanted tooffer my twocents as i feel the game could benifit fromsomthing like this and given how it's shaping up wouldn't be difficult to do story wise. This could be saved till after a girl is finished with the 'control' changed to 'influence' or 'affection.' lust can be the same of course.
What do you think?