I don't want to spoil anything so I'll write a review without doing so.
This anime got dark very quickly. It starts off as a sweet high school love story but ends gruesomely. The girls are seen solely as sex toys and nothing other than that. It wasn't too bad. But i just dislike the way that the characters think. The only decent character in the entire anime is Katsura's little sister, Kokoro. I liked Katsura first but after she started to lose herself.. not so much. Overall though, the plot was very interesting and the ending just showed how prevalent the theme of "you reap what you sow" really is. So many unexpected scenes kept me engaged and entertained! I loved the ending I think it was well deserved lol. It wasn't bad at all. Most reviews are saying that it gave nightmares. I don't think it was that serious but hey, not everyone is the same.