I'm glad to finally see your writing attached to a game at last, Indigo! This was a neat little project, and I'm obviously inclined to love any visual novels.
Sensei struggling to sleep on his day off and fearing he's wasting it is a relatable set-up for two branching dialogue paths. I'm glad we get to meet Kayoko through one of them, too. Her route is cute, and referencing her early Momotalk events put a smile on my face. I'm glad you also made her CD bigger than just the clever joke about leaving it pristine. It felt game-accurate!
The smoking gun was another intriguing part, and I feel like you handled it pretty alright. In my deluded fantasy version of this, I'd love to see it be something that drives a narrative through multiple story beats.
On that note, however, I wondered why you opted not to use any sprites at all. It occurred to me that you might not have had access to the sprites (and hence the NVL mode throughout), but if you were using it as a statement, that's also pretty cool. At any rate, here is 1 and 2 for BA sprites if you ever want to use them. The alternate option in the choice menu not leading to any interactions with students was also a little jarring IMO. I can understand writing issues, but I feel like it's better to just not have anything at all if that's the ultimate result.
Don't let my critiques get you down, though. You made a game, and that's the hardest part! It gives me hope to see you go back to that older story about Alice you had last year.