The player must open up the Easter Egg menu and press the S key to activate this mode. This mode cannot be deactivated until the game is reset or the day changes. This mode turns all female students and teachers into skeletons, except the player and male students. The skeletons won't wear clothes but will keep their former hair. No males are affected because there is no male skeleton yet. The song, "Spooky Senpai" will play in the background.
- In previous installments, the music for this mode was Nyanners' cover of "Spooky, Scary Skeletons" by Andrew Gold. It has been replaced with non-copyrighted music in the February 17th, 2016 Build.
- The game's warning referred to this mode, saying that this game contained "Spooky Scary Skeletons". This warning was later removed because YandereDev said that it was "cringey".
- This mode was implemented in the August 12th, 2015 Build.