Man, fucking finally getting this gem after searching for hours for a similar game to dissonance, as I played that first before this. Honestly, before playing I thought it would be another koikatsu style game that is common as I got my expectations dashed but after playing through, I got really pleasantly surprised by the similar sandbox gameplay , supernatural background and personality traits of the student in that game. Also amazing plot and artwork, can't express how to finally play a good game. Another game I believe lost in you drew inspiration from would be lessons of love although it is way too disturbing for me, tried to play through until I had to give up at the scene. Honestly, if you guys know of any other similar games please do so
Welcome to the Friendship Club and Two Sides of the Same Coin are other two games from this "genre" i've personally labelled as "LiL-Likes" (Dissonance being one of the biggest), but TSOTSC is kinda rough because it was the author's first work if i remember correctly.
There's also Another World, but that doesn't really have the same vibe.
I've played both games you mentioned, OOT was a bit too western for my taste so i didn't complete it but i completed AD's lastest update, both are pretty good in my opinion.
And as someone who pretty much played all of those, i'll agree Dissonance is the lightest one, a claim really pushed by the fact it's probably the only one without a depressed protagonist. Another LiL-Like i recently got into is Kaleidoscope, but that one kinda suffers from wanting to be too much like Lessons in Love without actually having the courage do what Lessons in Love does.
LiL seems to be very polarizing, either you love it or you hate it. If you liked this game i would recomend it with the caveat that you should grab the Progress and Guide mod from F95 as with up to 30 heroines the outdated design can become very frustrating.
I'm not sure if 4 years was enough for you to be met with the re-write of the early game should you chose to replay it.