Memory-Concealing Manipulative Sand Technique

The user seals away the target's memories by burying an extremely small needle into the brain's memory centre. The memories can be restored by cancelling the technique, thereby destroying the needle. If a subordinate had this operation done on their brains and has infiltrated in enemy camp, they can safely perform spy activity over a long period of time. If the user cancels the technique, the target will once again remember their mission.