There's "Saki Sanobashi", although its existence is disputed.
From
https://knowyourmeme.com/memes/subcultures/saki-sanobashi :
>Saki Sanobashi is a supposedly lost horror anime about the violent deaths of girls trapped in a bathroom. Since it was brought up in a forum post in 2015, other users have described seeing something similar, leading to a quest to find this supposed lost anime.
>On February 21st, 2015, a user of 4chan's /x/ (Paranormal) board described having watched a strange and violent anime named "Go for a Punch".
<Some weird anime about naked girls stuck in a large bathroom without doors, having a philosophical debate about never getting out of the room. After losing hope and starving for some days everything goes downhill.
<They just start screaming and yelling.
<Then they all commit suicide, either by smashing their heads on the floor or scratching their necks to bloody pieces
>Another user asked the /a/ (Anime) board if they knew about it and was told that the title might be Saki Sanobashi. Most people thereafter used this name for the mystery anime.
Sounds pretty bizarre and disturbing.
