A space-time technique that allows the summoner to transport animals across long distances instantly.
One method involves just hand signs and blood. With this, before an animal summoning can be performed, a prospective summoner must first sign a contract with a given species. The contract can come in the form of a scroll or a tattoo, which is signed in the contractor's own blood. After this, they need only perform the hand seals, offer an additional donation of blood, and use the same hand they signed the contract with to summon the creature.
An alternate form of summoning is to just use a scroll without any hand-signs. In this case hand signs are not necessary, with energy not even being necessary sometimes. By using this method, one can summon creatures with whom one does not have a contract with.
When an animal is summoned it is transported from its place of residence to the summoner's location. Once summoned, the animal can perform a task or help the user in battle. The summon is not required to help the user, and may be more of a hindrance than an ally. In addition, summons are able to summon their summoner.
Items can be "summoned" from scrolls. Because the items are not summoned from anywhere, instead only being released from storage, no blood is needed and thus it is not a conventional summoning. Characters have on occasion been shown summoning weapons such as kunai and giant shuriken, sometimes without hand-signs