Akino

is a ninken and a personal summon of Kakashi Hatake.

Background
In the anime, after they made a contract with Kakashi, Akino and the other ninken aided him to search the abducted Rin Nohara by the Kirigakure shinobi and acted as a diversion in order to allow them to flee. They also helped searching for the fleeing Orochimaru.

Appearance
He has tan fur with one white strip starting from the top of his head and going down his muzzle. He wears sunglasses and the standard outfit of Kakashi's ninken, consisting of a blue vest with the heno-heno-moheji seal and a Konoha forehead protector around his neck.

Abilities
Akino is among the ninken that has demonstrated the ability to speak. He also has heightened senses with which he can use to track his target with ease. He has also demonstrated the ability to track his target underground through the use of the Summoning: Earth Release: Tracking Fang Technique as well as hold a target down, allowing Kakashi to attack them freely. He also along with exceptional teamwork with the rest of his pack, able to develop and effectively use several offensive and defensive formations in battle which make use of the manoeuvrability and powerful limbs.

Prologue — Land of Waves
Kakashi called on Akino and the ninken pack to track and capture the missing-nin Zabuza Momochi. They managed to bite onto the missing-nin and pin him in place. This allowed Kakashi to use Lightning Cutter without fear of a counter attack.

Sasuke Recovery Mission
Later, Akino and his fellow ninken were summoned by Kakashi to track down Naruto Uzumaki and his team who had gone off in pursuit of Sasuke Uchiha.

Sunagakure Support Mission
In the anime, he, along with the other ninken were summoned by Kakashi to investigate the Takumi Village.

Kazekage Rescue Mission
Akino and the ninken pack were called upon to track down the Akatsuki member Sasori, using a small piece of his clothing.

Itachi Pursuit Mission
Kakashi summoned the pack to help track down Itachi Uchiha. He and Guruko were partnered with Shino.

Five Kage Summit
In the anime, Akino was seen along with Urushi, Shiba, Bisuke and Ūhei being deployed by Kakashi each carrying scrolls with intel for the other hidden villages.

Kakashi Hiden: Lightning in the Icy Sky
Kakashi summons Akino and the other ninken to search for the exploding tags planted around the Tobishachimaru. Once they gather all the tags, the ninken give them to Might Guy.

Trivia

 * Akino was initially shown to have completely tan fur in the anime. This was later changed when he was coloured in the manga.