I was really intrigued at the premise, I think a bit too many girls at the same time for my taste especially for a new game. I'm of the minority that I like that the NTR antagonist is someone people don't like since to me that's the appeal in NTR. It's more deprave knowing someone you don't like, maybe even someone you look down on is the one NTRing you and since we're Shiro here I think it fits well. Would welcome anymore other guys though since just 1 guy doing all the girls is going to get monotonous real quick, I think there's hinting at a pervy principal and maybe some guys at school who could add more spice.
Can't say I fancy the immediate they're just sex slaves immediately, that's a bit meh there's no more tension of will they won't they fall since they HAVE to comply. I liked the idea presented earlier about Saber can't fight back as to not stand out and possibly trying to blend in. Or Rin/Sakura trying to pretend to be single to also not make things weird but things backfiring there. The forced "ok now my sex slaves who do everything I want whenever I want" seems a bit forced. Plus maybe because Shiro has 5 girls immediately Shinji fucking one of them every other day doesn't exactly feel like a loss on his part? Idk. I'm gonna look out for this one and have high hopes though because of the setting and art not being bad. Just hope there's more situations and not just Shinji dropping by picking a girl, having a secret scene behind Shiro's back and repeat for the next few days. Congrats on releasing a game!