1. The Fruit of Grisaia
(> 50 hours)
2. The Labyrinth of Grisaia
Long (30 - 50 hours)
3. The Eden of Grisaia
Medium (10 - 30 hours)
3 Games from the same series. Perhaps even connected but i am not 100% sure.
Other series games like Corona Blossom and Neko-nin, Nekopara could be what you are searching for.
https://www.fakku.net/search/grisaia
https://www.fakku.net/games/ideology-in-friction-english
https://www.fakku.net/games/ideology-in-friction-append-english
Seems one of those games has controversial tags. If so, you need 15+ posts in the forums and have to put the controversial content filter "on" under "my account" -> "Settings" -> "Account Settings" -> "show controversial content"