Jiraiya using a barrier ninjutsu.
Barrier ninjutsu (結界忍術, Kekkai Ninjutsu, literally meaning: Barrier Ninja Techniques)[1] are techniques that impose an effect upon a defined space.
The term itself is rarely used in the series and in fact never clearly defined, but several different jutsu are said to create or utilise barriers (結界, Kekkai), all of which serve one of a few broad purposes:
- Most commonly, barriers are used to limit passage through or access to an area. This can be done to prevent unwanted intrusion, as with Uchiha Flame Formation, which creates a barrier of flames around an area that burns anyone attempting to enter. Alternatively, such barriers can limit escape, as with String Light Formation, which restricts the movements of those within it. These barriers do not need to be active at all times: Barrier Talisman: Armoured Eye only activates when the eye it protects is under threat. These barriers do not even need to affect all individuals: Sealed Iron Wall only blocks entry to those who lack the Gift of the Hermit Group; the barrier protecting the Naka Shrine can be lifted by performing the correct hand seals.[2] Barriers can be overcome if whatever creates the barrier is neutralized, like removing the sealing talismans that produce the Five-Seal Barrier or attacking those who maintain the Four Violet Flames Formation. Barriers can also be broken through sheer brute force: Naruto Uzumaki and Killer B escape thirty-six layers of a Self-Repairing Barrier by using a Tailed Beast Ball. Space–time ninjutsu can be used to circumvent all barriers such as these.[3][4][5]
- Barriers can be used in service to space–time ninjutsu. At times this is done for transportation: Flying Thunder God: Guiding Thunder teleports anything that contacts its barrier to a designated location; the long-range version of Kamui creates a "barrier space", warping anything within that space to Kamui's dimension. Alternatively, barriers can isolate one dimension from another, as is done with certain types of toads: diving toads conceal those stored within its stomach, meaning that only the toad's presence is at risk of detection; gourd toads trap those it pulls into its stomach, cutting them off from allies and subjecting them to the stomach acid and other perils found there.
- Rather than impede or aid traversal, barriers can facilitate sensory ninjutsu within the affected area. Barrier: Canopy Method Formation forms a barrier around the user, helping them detect anything moving within their vicinity. A Sensing Barrier alerts its users to unauthorized entry to an area, though actually tracking intruders after they enter relies on another technique.
There are a few barriers that don't fit neatly into any of the above categories. Barrier Method Formation serves as a sort of booby trap, triggering explosive tags when anyone enters its perimeter. Four Black Fogs Formation places those within it into a sort of stasis, protecting them from outside forces, notably death. Earth Release Barrier traps the user's opponents in a prison, but such physical confines are not ordinarily called a "barrier" elsewhere in the series; the constant absorption of its captives' chakra is perhaps the actual reason it is called a "barrier".
Trivia[]
- The term kekkai (結界, literally meaning: fixed boundary) is of Buddhist origin, originally referring to cordoning off/restricting access to areas that pertain to religious practices (e.g., sacred places within which monks are to be trained), or wooden fences/partitions physically separating a temple's inner and outer sanctums. In contemporary Japanese fantasy fiction, especially manga and anime, the term usually refers to protective, magically or spiritually erected "barriers" or forcefields.