Hateful Mode is a reference to the video game Hatred. Press H to activate this mode. It cannot be deactivated until the game is reset or the day ends. Yandere-chan will resemble Hatred's main character, "The Antagonist". Her hair will become long, black, and raggedy. The School Atmosphere, Yandere-chan's uniform, and her skin will turn monochrome, The song, "Hatred", will play in the background the entire time.
In Hatred Mode, Yandere-chan's sanity is set to minimum. Because of this, if Senpai or a teacher sees her insane, it will be an automatic Game Over. Yandere-chan's reputation will be damaged if any students see her. She is able to get her sanity back by laughing insanely or by viewing Senpai's profile at the phone gallery.
- When the player wears gloves then takes them off, Yandere-chan will be wearing the normal school uniform instead.
- This mode was implemented in the April 2nd, 2015 Build.
- The player is able to wear the hair from this mode by pressing H.
- This music for this mode was created by OnlyWednesdayMusic.
- There was once a bug where if the player changed outfits in the Shower Room in this mode, Yandere-chan's entire body would warp into a terrifying inhuman figure. This bug was later fixed. The game's warning made a reference to this as it said the game contained "Eldritch Monstrosities", the same description for when YandereDev patched the bug in the August 18th, 2015 Build. This warning was later removed because YandereDev said that it was "cringey".
- Hateful Mode shares the same hairstyle with Horuda Puresu.