Boar-Masked Anbu Member

He is an Anbu Captain from Konohagakure.

Background
In the anime, he, Kakashi Hatake and his partner came to the aid of a Konoha lookout that was getting attacked by a group disguised as Iwagakure shinobi, with the intention to create a rift in the peace treaty between villages. Soon after they arrived, the group retreated leading Kakashi to follow them and mercilessly kill all five of the shinobi before their group could collect intel from them.

He and his partner accompanied Hiruzen in infiltrating a secret bunker with the intention to find out who was behind the kidnapping of Anbu and jōnin in the village. After they disarmed the traps, they confronted the person behind the acts and discovered it was Orochimaru. Having been caught, the Sannin attacked the Anbu and Hiruzen and escaped. Afterwards, he and other Anbu were tasked by Hiruzen to capture him alive if possible, before he left the Land of Fire.

Appearance
He is dressed in a white cloak and black trousers with bandages tied around his right leg and black sandals. He also has brown hair tied into a short ponytail, and wears a mask with a boar motif inclusive of three markings at the top and bottom of it along with markings around the mouth and eye-holes. In Part I, he wore the standard Anbu attire and wore a sword strapped to his back.

Abilities
Being an Anbu, he is presumably capable of using kenjutsu as he wields a sword and can perform ninjutsu such as the Temporary Paralysis Technique, which can subdue large animals and can perform the Shadow Clone Technique. He is proficient with using Earth Release in conjunction with Space–Time Ninjutsu to drop gigantic earth structures to crush his opponent. In the anime, his skill in Earth Release is expanded upon as he is able to use the Earth Release: Hiding in Rock Technique to move through the ground undetected and he can open a portal in the sky to drip mud on his opponent, which encases and traps them.

Chūnin Exams
In the anime, he and a squad of Anbu attacked and caught Hanare before she could infiltrate Konoha. After escorting her into the village, he handed her over to Ibiki Morino and the Konoha Torture and Interrogation Force to get information out of her. Later, he and his partner stood guard during a meeting between Konoha representatives and the Fire Daimyō. When someone interrupted the meeting, he and his partner immediately restrained the intruder.

During the Chūnin Exams, he and his partner went to retrieve Anko Mitarashi in the Forest of Death. After seeing that her cursed seal had resurfaced and hearing that she had encountered Orochimaru, he told her that martial law was to be implemented whenever he was spotted and as such the exams should not continue any further. After carrying her back to the tower in the middle of the forest, their attentions are drawn to a video by Iwashi. They then discuss the progress of the Three Sand Siblings to the tower, who are unscathed. After Kabuto Yakushi killed the Anbu stationed at Konoha Hospital which were gaurding Sasuke Uchiha, he, his partner and Yūgao Uzuki randevu'd at the hospital and discussed the matter with the Third Hokage and Kakashi.

Twelve Guardian Ninja
In the anime, he was seen alongside his partner watching Danzō Shimura under Tsunade's orders.

Three-Tails' Appearance
In the anime, he and his partner were part of a Anbu team that was tasked to watch over the Three-Tails. After arriving and relieving Kakashi's group of watch, the group stationed themselves at the lake to write reports to send back to Konoha. While on watch, he and his partner were attacked by Deidara and quickly defeated.

Itachi Pursuit Mission
In the anime, while patrolling Konoha's graveyard with his partner, Kabuto managed to sneak past the two, dig up the graves of three shinobi and get their DNA.

Pain's Assault
During Pain's assault on Konoha, he was part of a three man team with Zō and another Anbu captain. When the team encountered one of the Animal Path's summon's, they notified an Anbu that was at the Konohagakure Intelligence Division. While the other captains immobilised and trapped the dog, he summoned a gigantic earth structure to crush the summon, but the attack was unsuccessful. After releasing that it was a special kind of summon, they began searching for the summoner. When Pain attacked the Intelligence Division, he and the other Anbu assisted Ibiki while Inoichi's group escaped. As they attacked the dog again, they used "Formation B", but was unsuccessful again. After being injured, Katsuyu attached herself to him and began healing his wounds. The Anbu captains continued fighting the Animal Path until she retreated and de-summoned all her summons in Konoha. After Pain destroyed the village, he and the other captains survived the attack and guarded Ibiki, while Katsuyu healed him.

Video Games
In game, he and Anbu Commander help the Third Hokage fight Kurama until Minato comes to the rescue.

Trivia

 * This Anbu and his partner both share the same mask and hairstyle with two Hoshikage Anbu.