So I just read Chapters 1-3, and... I like it so far. There are, however, some glaring issues. I'll probably read the remaining chapters later, but in the meantime, this is what I found:
First of all, this is in need of a proofread. The main thing I noticed was commas missing in places like: "What the hell was that, MC?" If you address the person you're talking to in a sentence, you put a comma in front of it and behind it, unless there's already a period (or question mark, like in the example I gave). Also, nicknames like "Sweetie" or "Princess" should be capitalized.
Tenses are sometimes messed up, too. For example this line in Chapter 2: "So you are the mysterious MC that Nina talks about non-stop since a week." should be "So you are the mysterious MC that Nina's been talking about nonstop for a week." And, yes, nonstop is indeed written without a hyphen (had to look that one up).
Oh, and since I'm telling this pretty much every dev: "Ok" is not a word. "Okay" is. And pretty often, there's a comma behind it.
Secondly. Options are nice. You can spy on Lily in the shower, bury your face in Hitomi's crotch during the pool scene, touch Nina's boobs when you put her to bed. And you can decide against doing those things. The problem is, besides not showing the MC doing those things, the game still seems to think he did. I'm doing a playthrough avoiding these options whenever I can, and the MC and the other characters constantly reminded me that I did things I didn't do.
On the example of Lily's shower scene: The next morning in the shower, MC remembers watching her and uses her (and Megan, but mostly her) to jerk off, making a comment about it afterwards as well. Then, when Lily finds his sperm in the shower she says she saw him spying on her. And that night when she comes to him drunk, she tells him she saw him. None of which should be possible.
In the same way, when Nina talks to MC about how she doesn't think she's girlfriend material, you can either tell her she is perfect GF material and cute, or you can just wave her off. But no matter which you pick, seven lines after your response, she'll ask you to confirm your positive answer. This piece of software somehow has an even worse shortterm memory than me!
And to finish this point: All those choices allow you to gather points for the girls they're about. But in the whole script so far, the only time these points have mattered was in Chapter 1, when the dialogue changed based on whether or not you have collected the one available point for Lily. Why give us choices at all if they don't matter and the game essentially forgets about them ten seconds later?
This is one I don't think I've ever complained about. I've noticed a couple times that the renders don't quite fit what's happening. When Nina leaves to see Hitomi and just walks past Megan and the MC, even after we read that she left, she's still visible for the rest of their interaction. And later, when Lily asks to sleep in the MC's bed, he already has his arms around her before she asks him to hold her.
It also seems like Megan's model is constantly grainy, while I've noticed no such thing for the other characters.
There's a little error in the scene where Lily and MC wake up together; an undefined variable in an if statement.