Kuchiyose no Jutsu

From Naruto Fanon Wiki

Name: Summoning Technique (口寄せの術, Kuchiyose no Jutsu; Viz "Shinobi Conjuration", English TV "Ninja Art: Summoning Jutsu")
Type: C-rank, Offensive, Defensive, Supplementary
Users: See below
Hand Seals: Boar, Dog, Bird, Monkey, Ram, Palm On Ground (Jiraiya uses left, most other characters use right or both in some cases).
Debut (Anime): Episode 17
Debut (Manga): Chapter 29

The basic form of all summoning techniques, this jutsu uses a contract, hand seals, and the user's blood to summon an animal or weapon from another dimension, which usually manifests once the ninja summoner strikes his hand against any surface, after which the specific summon will appear. As an alternative to the normal hand seals, the same contract that appears on the ground during the summoning can be drawn by hand and activated, producing the same result. The type of animal summoned is determined by the contract. The blood is used as a signature to make the contract, which can be written on a scroll or tattoo, valid. Once summoned, the animal can perform a task or help the user in battle.

Most summons (if not all) appear to have their own "king" or "boss" that rules over their own kind. For example: to the Toads there is Gamabunta, for the Snakes there is Manda, for the Slugs there is Katsuyu and for the monkeys there is Enma.

It would that seem that once someone has signed the summoning contract, the animal of the contract can also summon the human, as seen with Gamakichi summoning Naruto to the toad mountain.

Specially prepared scrolls are used for any weapon summons or a variety of articles, such as puppets. Kankuro, Tenten and Kotetsu Hagane use this version of the technique.

The summoned animal is usually subservient to the summoner; however, the more powerful summons, such as Gamabunta and Manda, demand respect and loyalty from their summoners. Manda even demanded a hundred live human sacrifices on one occasion.