Kamui is a powerful Mangekyō Sharingan dōjutsu that creates a unique and specialised form of space–time ninjutsu. It allows the user to achieve two very distinct, yet closely associated feats — teleportation and intangibility.
Kamui allows the user to transfer targets to and fromanother dimension, from which they are unable to escape. Kakashi likened the characteristics of this technique to those of the Flying Thunder God Technique, but noted that it seems to be more advanced, as it requires neither seals nor a summoning tattoo to be performed. Minato Namikaze admitted that this technique exceeds both his and the Second Hokage's space–time ninjutsu.
This technique forms a spiraling void centred on the eye used to activate it, which draws the target inwards and distorts their form until they are transported to another dimension. By absorbing their own body into this distortion, the user can teleport to virtually any location they desire. When using Kamui to teleport, anything the user is touching will be warped along with them, and their chakra becomes untraceable. With a single eye, this technique was fast enough to avoid an attack from Naruto Uzumaki in his Nine-Tails Chakra Mode, though slower than the speed at which the Truth-Seeking Balls travel. However it was not fast enough to avoid any Attack by Shisui Uchiha II in his Two-Tails Chakra Mode.
After storing a target within Kamui's dimension, the user can then eject it from their eye at any time. This can be done with varying degrees of force, allowing the user to eject weapons at a moment's notice, giving opponents little opportunity to react accordingly. Despite not always being present, Obito could keep targets under genjutsu while they were confined inside Kamui's dimension, thus keeping them incapacitated for extended durations.
Kamui can synchronise with another space–time ninjutsu, granting the user access to the synchronised technique's dimension, as well as any other connected dimensions. Once the dimension has been marked, the user can freely travel between it and Kamui's own dimension.
Obito Uchiha / Kakashi Hatake
Obito's left eye is able to utilise a long-range version of Kamui, which can transport targets anywhere in the user's line of sight. The target is surrounded with a barrier space, the location and size of which can be specified at will, and when the user concentrates on the target within, the space at the barrier's centre distorts and draws everything within into another dimension. The size of the barrier can be expanded, as Deidara was forced to fly further away in an effort to escape its effects.
Obito's right eye uses a short-range version of Kamui, which can only transport targets in close proximity to the user; physical contact with the target is seemingly required. However, this eye can utilise a unique variation of teleportation akin to intangibility. When activated, any part of the user's body that overlaps with another object is seamlessly warped to Kamui's dimension, making it appear as though the user can phase through solid objects. By overlapping their entire body, the user can completely conceal their presence and erase all traces of their chakra. This also allows the user to freely travel through the ground, enabling them to ambush opponents from below. This intangibility can be extended to anything the user is touching at the moment of activation, so long as they are able to maintain physical contact with at least a portion of the desired object. This ability also allows the user to bypass even the strongest barrier ninjutsu.
When both eyes are used together on the same target, the teleportation process works twice as fast, even becoming faster than a Truth-Seeking Ball used as a projectile. Through both eyes, the user can create two distortions at the same time and connect them. This was demonstrated when Obito first used the left eye's Kamui to synchronise with Yomotsu Hirasaka, then used the right eye's Kamui to teleport through the portal into another dimension. The user is also able to create portals in their line of sight to connect two dimensions. Using both eyes in conjunction with the Six Paths Chakra allows the user to augment their other techniques, transporting targets struck by said techniques to Kamui's dimension.
Shisui Hashirama Uchiha II and Minato Uchiha
Left Eye/Right Eye
Shisui Hashirama Uchiha the Second was unique because he could only use Long-Range Kamui. It was believed to be an Isolated Case, but Later on Shisui's Son, Minato Uchiha, had the same. Except that he could only use Short-Range Kamui, it was Discovered that both Father and Son using Kamui on the same target would cancel them both out. This was believed to have been as a result of a Genetic Mutation.