Kuchiyose no Jutsu: Ookami (口寄せの術狼, Ninja Art: Wolf Summoning Jutsu) is a ninjutsu that allows the user to summon various different wolves to their side; though this is only possible if they've signed the wolf contract that's unique to the Seishi clan. There are numerous members of the Ookami clan, though some are more useful than others.
The contract that they are connected to, as earilier stated, is used exclusively by the Seishi clan. These wolves are different from your regular summons in such a way as they have the right to refuse a call, or a summoner, though it's not often they do this. The summons that make up the contract are the family of one of the wolf that Aisu Seishi saved, and who later would save her daughter in return.
Current Clan Members
A description of some of the summonable members of the Ookami clan, and what role they play within the clan.
Yuuki (優希, Gentle) is a young wolf with inky fur and green eyes. She is one of the fastest members of the Ookami clan, and usually plays messenger for Shiki when needed. Kuroko is known for her obedient yet happy behaviour; she does defy orders on occasion, but only when she deems it necessary. Just because she plays messenger, however, it doesn't mean she's weak in combat; she's not as strong as others of her clan though.
She first appears during the mission to Wave with Team 7 and 8, when Shiki sends her back to deliver a message to Sarutobi, regarding their decision to continue on with the mission. Ever since, Yuuki has been firmly portrayed as the messenger wolf.
Akane (茜, Brilliant Red) is a large, fully-matured wolf who sports thick, light-silver fur and ruby red eyes, hence the name. She's known for her more protective, agressive behaviour when it comes to watching out for people, or things that she trusts/loves. Akane usually plays the guard for clients when on escort missions, though her large size and intimidating look often scares them. She's one of the stronger wolves within the clan, though quite a few can easily beat her in size.
Akane first appears during the inital fight with Zabuza. Shiki leaves Akane to protect the team whilst she watches over the fight, or more specifically, makes sure Kakashi doesn't get killed. Akane is summon on occasion, when Shiki feels that something needs protecting, Akane is the first to be called.
Riku (陸, Land) is a male wolf with chocolate-brown fur and green eyes. He has an earth affinity, and can utilize this to his advantage; he can use this for the offensive, but he is more commonly used, and better suited for, defensive combat. Riku stands at about Shiki's waist and is occasionally used as a means of transport, if needed.
Riku makes his first appearance on a mission gone wrong with Shiki's Anbu team, who are trapped and forced to outrun their enemies. He creates a barrier of earth, protecting one of the fortunate Anbu from being stabbed in the back with a kunai. He continues to make appearances, though not as often as others of his clan.
Shigeru (茂, Luxuriant) is a male wolf who is known for his playful behavior and dependent personality. Shigeru is large, standing easily at Shiki's chest, with reddish-brown fur and bright blue eyes. He's commonly used as transport, due to his speed, and is the youngest son of the current clan head.
He is first called upon to get to Sunagakure quicker when Itachi can no longer put up with Team 7's complaints, Shiki was quick to summon Shigeru as a way of transport. He has since been called upon numerous time, whether to carry injured teammates or just give a lift.