This mode is a reference to One Punch Man. Press O to activate this mode. It cannot be deactivated until the game is reset or the day ends. Once pressed, Yandere-chan will resemble One Punch Man's main character, Saitama. She will don a yellow full body jumpsuit with red boots and gloves. A white cape billows behind her. The player will have a bald head as well.
The player can use this mode to kill students and teachers. If the player presses the Left Control key, they will punch the air. If any student is in the way, the corpse will fly far away due to the strength of her punch, replicating Saitama's fighting style. If any NPCs see the punched student, they will treat it as a regular corpse, so Heroic and Strict NPCs will not attack the player. The punch has a very small hit box, so the player has to be very precise in aiming at the target.
- The mode's skin textures will break if they wear gloves.
- Usually, if a student is one punched, their ragdoll physics will break.
- This Easter Egg was implemented in the January 1st, 2016 Build.
- The original song of this mode was "THE HERO !!". It was eventually removed in the March 16th, 2016 Build.
- The game's warning referred to this mode, saying that this game contained "impossibly strong punches". This warning was later removed because YandereDev said that it was "cringey".
- Due to the delinquents' pushing hitbox, it is not possible to punch a delinquent.