Nani mo Iwanai
It has complicated but interesting stories. Some of them were a little dark but the 1 one has the most interesting plot. Because we can see those character had some... issues, but they don't do anything completely "evil" or even something I have never seen before. I've seen plenty of girls go for sneaky tactics like those to "steal man" from each other or manipulate them, so it's interesting to see it from an outsider perspective. It hits you how powerful the act actually is and how we chose to soften it in real life.
Kawaii Senpai no Kaigoroshikata
This is a pathetic excuse of a psychopath getting his way without any punishment. They even try to make that relationship look cute somehow! No my cup of tea at all. Terrible.
Yandere Hitotsu Yane no Shita