I read this really weird manga called "Fasting" the other day. It's pretty short, it's about a girl with an eating disorder and it gets so abruptly creepy at the end that it's kinda funny in a twisted way lol it just came out of nowhere. Another one is "Blood Slurping Darkness," which is also about a girl with an eating disorder but it starts getting weird pretty early on (it's also short). I'm not sure that I'd call either of them "good" really but they definitely disturbed me lol. I should've known that the first two eating disorder manga I found would be some bizarre horror stuff. Oh japan.

Oh! I started reading this one horror manga called "Higanbana no saku yoru ni" and the subject matter it deals with is highly disturbing in and of itself. The main character is a little girl who is being sexually abused by her teacher and it gets very dark. Some of the dialogue is kinda narmy but there's this whole plot about "the seven mysteries" at the girl's school, which are a bunch of urban legends that are actually real and controlled by spirits. I never finished it though