I really liked it! Scenes were nice and character designs too (especially Tomoe's outfit I'm digging, hope she wears it again), dialogue wasn't bad at all, didn't notice any flaws. I've seen way more cheesey dialogue with bad english, but this one felt really well thought out. The scenes and 3D characters looks nice, not sure how Koikatsu CharaStudio works, only saw some skirt clipping but that's fine. The sword fight scene was awesome.
I do like the twists and turns the story took, from opponent having the upper hand and getting her fun, then getting back at her, usually the stories only has one or the other. I also liked Yoko approving her lover to rape her opponent and she's the one all into it, not enough scenes like that (or any) and I'd definitely wanna see more of.
I hope you continue it, definitelly interested in its continuation!