Kaihengan

The Kaihengan (改変眼, Literally meaning: Altering Eye) is a dōjutsu kekkei genkai not belonging to any specific clan that is known of, and seems to appear selectively throughout the world. It's origins are also unknown.

Abilities
The Kaihengan has the ability to fabricate, alter, or remove memories in the target. It can also sense and measure the strength of a person's chakra. When being used, the Kaihengan locates and targets specific chakra releasing nodes in the brain that are linked to memory. It then can see memories and alter, create or remove specific parts or whole memories. In Inko's case, she removed most of her existence from the memories of those in Konoha.

Depending on the complexity of the memory being made, altered or removed, this can take up to a few minutes and can leave the user vulnerable to attack. When someone's memory has been manipulated either multiple times, or for a long period of time, the user's chakra signature can be absorbed into the target's chakra and will often display flashes of the Kaihengan in the person's memory; either when recalling the new memory, trying to remember a forgotten memory or when trying to recall the user, if the user has chosen to also remove the memory of using the technique.

Fabrication of Memories
The user can write out entirely new memories on the intended target to their liking. This takes anywhere from a matter of seconds to a few minutes. It is most useful for manipulation of a large group of people, and spreading lies to create civil war, coup d'etas, and any other matter of conflict. It can also be used for good purposes, but it's most practical use is to manipulate conflict.

Altering of Memories
The intent of memory alteration is to remove presences from memories, confuse the person, or groups of people by adding or removing details, or to even transfer minute details of one person's memory into another person's.

Removal of Memories
The user can completely invade and remove memories, causing amnesic like symptoms in the person. Risky but doable uses is to also completely erase the person's identity, potentially making them forget any abilities, information, jobs or missions they have been given. It is also useful if the target wants to forget and consents to full memory obliteration, to avoid leaking intel. This is the only technique that can also be used on the user of the Kaihengan.