Judging the alpha 0.1 up to the rat crash, I have to say I'm very pleasantly surprised. The art is great but we all knew that already. What I like about the alpha is the composition and the writing. It's not novelist tier, but still really good. Technobrake respects the rules of storytelling for the most part and I like the small cliffhangers that make you want to play further.
The ring as a plot device seems interesting, and it seems that instead of including NTR just for hentai's sake, it could actually be explained by the story. It's implied that the ring lets the wearer attract perverted people of the opposite gender by fate. That's why Jimmy met Kohaku after putting the ring on. Shortly after, Kohaku puts the other ring on her finger. My guess is that the ring will work exactly the same and attract lots of perverted dudes from now on, leading to many NTR attempts. So it's not like every dude in the game is a pervert, Kohaku just attracts many perverts because she chose to wear the ring.
My favorite scene in terms of how it was crafted was when Kohaku whispered into Jimmy's ear that she's a nympho. The music track for the scene was very well chosen and I liked Jimmy's reaction and the hint of crazyness coming from Kohaku. Reminded me a bit of other popular Yanderes. However, I think that Kohaku's confession of being a nympho came way too soon. I think there could have been a much better arc of suspense if Kohaku hid her kinky side a bit longer. You would play as Jimmy, who's not aware of what Kohaku does when he's not looking, but of course you as the player know what she's doing because you are looking at the events from above. And slowly, you would see how Jimmy finds out about Kohaku's lewd side (peeking through the door while she masturbates, wondering why your coffee tastes weird and why the mug is wet on the outside, wondering if you just imagined the hole in her uniform or if it was real etc). Lots of wasted potential here.
Nevertheless I'm excited to see where the game goes from here. We finally got to see Iris in game, so that's already a highlight for me. The store clerk sure has some fans as well, and I'm excited to find out what the fortuneteller meant when she said that Kohaku has an interesting bloodline.