He cares, trust me. I only got some of the dialog since I only use translator for choices in trials but every now and then my eyes would glance over at dialog....and he gets pretty defensive over the girls for various reasons (girl he likes, little sister, little sister's friend that protects her, because she's hot (?), because she's hot). Just he's pretty much like the other guys in this game, open to his desires. And personally, I enjoy having an NTR game with an MC like that. I more can't stand the ones who turn down other girls to be faithful to the main heroine even when he knows or highly suspects her being with another guy. That doesn't make the NTR stronger or more satisfying to me, just plain illogical.
The one thing I really liked is for sempai/girlfriend to get her first sex scene on day 1....you have to rely on other guys getting her stats up. If you come to her rescue in the morning and afternoon, her stats will be too low and all you'll get is a suplex when asking her for sex. And I think the same thing will be vital to get sister's friend and teacher. You'll have to balance when to let the girl you're after get groped and rescuing her so that you can get the stats required. Though some rescues end with the MC groping them instead lol.
lazycat
I don't think additional days would help with sister's friend/teacher. Since getting the required stats naturally on my end and even your using cheat engine to get stats didn't work....they most likely been locked out. By day three, both of them should have enough points to at least be able to succesfully grope/kiss/lift skirt and not insta-ko. But more time would at the very least let the other guys build more love stats so we can see NTR scenes. I also wouldn't mind seeing a 2nd sister scene like the 2nd girlfriend scene. Wait, now that I think about it....Evening of day 3, if you haven't done any teacher events.....you can't click on 1st year classroom period. Something hidden there?.........or probably just a bug lol.