Karin

Karin is a subordinate of Orochimaru, a former kunoichi of Kusagakure, and a member of the Uzumaki clan. She assisted Orochimaru in his experiments, and was left in charge of his Southern Hideout while he was away. She was later recruited into Sasuke Uchiha's group Taka, which was initially called "Hebi" at the time of its creation. In the anime, Karin and her mother were allowed to take refuge in Kusagakure, on the condition that her mother healed the village's wounded. After the village suffered huge causalities following a surprise attack, her mother upheld her duties and healed the wounded at the Kusagakure hospital, where she died after transferring too much chakra to the wounded. Immediately afterwards, the duty was passed onto Karin, much to her disapproval.

Some time after becoming a genin, Karin took part in the Chūnin Exams held in Konoha on a team. During the second phase, Karin lost track of her team-mates and was attacked by a large bear. She was saved by Sasuke Uchiha, who was disappointed to find she had an earth scroll as well, but she was able to catch a good glimpse of him, as he smiled at her. Her team later failed as they didn't make it to the tower with both scrolls by the fifth day. Soon after during a war, Karin sensed a huge group of people approaching the village she was staying in and hid while they attacked. After the village was burned down and everyone was killed, she was approached by Orochimaru, who asked her how she survived, leading him to bring her back to Otogakure. During her time with Orochimaru, Karin's healing abilities were studied by Orochimaru and Kabuto, with the latter successfully being able to replicate it. After being involved in experiments with Jūgo and Kimimaro, Orochimaru made her in charge of the Southern Hideout. In the anime, when Karin saw Sasuke for the first time since joining Orochimaru, she didn't realise he was the boy that rescued her during the Chūnin Exams. When the two formally met, Karin assisted Sasuke with recapturing one hundred and eighteen test subjects from one of Orochimaru's hideout, which they succeeded in doing. Sometime later, she was sent to the Eastern Hideout to deliver a vial to help further research on Suigetsu. Soon after Sasuke completed his task, Suigetsu escaped his chamber, leading to Karin taking action to hunt him down and joined Sasuke in an effort to recapture him. When they found Suigetsu, she attempted to persuade him into coming back to the hideout, which lead him to attacking her and repelled him with her chakra chain. After knocking him out, they brought him back to the hideout and parted ways.

Karin has a fluctuating personality; she will appear tough and in control at times, to the point of being violent and critical, and at other times will appear highly flirtatious. She possesses a strong dislike towards Suigetsu Hōzuki, whom she attacks whenever he decides to mock or berate her. In the anime, she stated that she was attracted to men based on their chakra quality, and claims that Suigetsu's chakra disgusts her. Sasuke Uchiha's chakra used to dazzle her, but it now scares her, due to it getting colder and darker from his hatred. Naruto Uzumaki's seems to calm and dazzle her as well, making her feel comfortable and relaxed due to it being warm and bright, though she also became scared after sensing an evil chakra within him. Karin develops a fondness for Sasuke from the first day they met; when he saved her life during the Chūnin Exams. In the anime, she has a flashback of when Orochimaru sends her to assist Sasuke in capturing a horde of escaped prisoners. There, she is captivated by the level of Sasuke's chakra and develops a sexual attraction to him. Karin's strong fondness bordered on fanaticism. For example, it was revealed that she had kept one of Sasuke's sweat-drenched shirts. Karin would typically insist that she has no feelings for Sasuke around others, while frequently suggesting to Sasuke that they should spend time alone with the intention of freely expressing her feelings to him, only to switch back to acting cold when other people are present. Despite Sasuke's chakra becoming increasingly "darker", she still found him attractive. However, after he stabbed her in order to kill Danzō and tried to kill her, then even order Sakura to kill her to test Sakura's intent to join him, Karin stated that she no longer cares about him. Karin has also used other's perception of her feelings towards Sasuke to her advantage, feigning mental instability while imprisoned at Konoha to make the guards pay less attention to her. Upon her escape, she follows Sasuke's chakra with the intent of aggressively confronting him about the stab as she vents her rage by furiously beating Suigetsu, but with Sasuke's apology and Orochimaru's suggestion, she found herself unable to stay angry. She even puts Sasuke's well-being above her own. Despite not being a combatant of Taka, she rushed into the battlefield with virtually no weapons or protective gear when she senses that Sasuke was on the verge of death, paying no heed to how strong the enemy was. In the anime, as seen in her Infinite Tsukuyomi dream, her greatest desire is simply to see Sasuke smile kindly to her. Even years later, even though she still loves Sasuke, Karin is content with the knowledge that he is happy with his new family. Karin also seems to have a soft spot for Sasuke and Sakura's daughter, whom she helped deliver when she was born and was the one who gave their daughter a pair of her glasses.