In the game, the katana is found in the Headmaster's Office locked in a case, with an explanation for that in the Headmaster's Tapes. YandereDev once stated that the katana could be something that the headmaster confiscated but never got rid of.
The katana cannot be concealed in the player's inventory and is seen as suspicious, so if any student sees the player hold the weapon, their reputation will be damaged by ten points (if the School Atmosphere is high).
The player cannot use a katana when fighting a Heroic student and will automatically lose, as the weapon is too unwieldy to use in close quarters.
- High Sanity: A diagonal slash through the student's stomach.
- Medium Sanity: Two diagonal slashes through the student's stomach.
- Low Sanity: The player knocks the student down to the ground and repeatedly stabs them from above.
- Stealth Kill: The player covers the student's mouth as they stab them from behind.
- Before the March 5th, 2016 build, when a mind broken slave committed suicide, the katana was so long that it clipped through her body and head before she stabbed herself. As of the March 5th, 2016 Build, a slave cannot be given a katana.
- Before the March 15th, 2016 Build, the katana killing animation was stabbing a student in the neck. It was not held over the shoulder either.
- The katana's killing animation is the same as the axe, baseball bat, dumbbell, the magical girl wand, and the shovel.
- As of the June 21st, 2016 Build, there is a placeholder sound effect for the katana.
|“||Is that a...katana? That better be a prop or something...||”|
— A student seeing Yandere-chan holding a katana.