I know this isn't an Anime. But it's a マンガ called Rabbit Doubt. It has 3 different series. Doubt,Judgment, Secret. This is really scary. I first found out about Rabbit Doubt when The アニメ Man Joey showed it in his 上, ページのトップへ 10 マンガ that should be an アニメ Video. And it kept me up scares of the dark for a few months. But now I'm getting over it. あなた should give Rabbit Doubt a try. There are scary Anime. But some Horror アニメ hasn't scared me yet. I seen Another and Corps Party. Didn't scare. Just way to bloody and gross. Lolz. Also DangonRonpa the アニメーション is a great Horror Anime. So is Tokyo Ghoul.
