I remember playing it years ago with a bootleg auto translator, so unless anything changed it goes like this:
There are several routes and different endings for each girl ( usually pairs of girls, since most girls in this game come in pairs, i.e. sisters or commander and servant, that kind of stuff).
The consensual route which is just you growing closer and eventually marrying them, it's generally vanilla stuff with tentacles mixed in.
Then there is the corruption route which involves corrupting said pair of girls (usually corrupting one of them and using her to corrupt the other). This is ultimately "Spicy Vanilla" with no ntr and just your generic fuck them until they go mad with pleasure. Girls become genuinely in love with you once you break them in good. I think there is only one instance when you have your girl give a blowjob to others or something, but it doesn't go past that.
And then there is the chaos route which is the fucked up route where you break everyone. In the final chapters you have to choose some of the broken girls to completely break them in to feed some sort of deus ex machina. Those events usually involve free use or sharing since you just throw them away to be raped. Ultimately i think it may be possible to sacrifice side hoes and keep all the main girls, or you can sacrifice main girls and get super free use orgy. You always keep your sister as your toy though.
TLDR: there is only one route where there can be Sharing/NTR and even then it's just you throwing away girls you don't like/need for plot reasons. If there are some girls you like you can keep them yours 100%.
