To See That Smile, Just One More Time

Summary
Karin gets caught in the Infinite Tsukuyomi. Inside her dream, Sasuke calls out for the kunoichi to wake up, but her only response is a request for him to smile. Several years ago, in Kusagakure, Karin's mother is being taken away by Zōsui to help with the injured, despite the woman's health condition. As Karin waits the entire night for her mother to return, Zōsui comes to pick her up, dragging her to the hospital where her abilities will be used to treat the wounded. While in there, the kunoichi learns that her mother has passed away and becomes horrified of the bite marks on her body. Zōsui delivers Karin to the medical team, telling her that she must earn her stay in the village. Karin begs her oppressors to stop, as an injured man bites her in the hand, but to no avail. Later, when she leaves the hospital, Zōsui warns the kunoichi to come back, even if nobody comes to pick her up, after which, Karin returns home, where she starts sobbing, recollecting her bite marks. A while later, Zōsui takes her to the battlefield, where she is to treat the wounded, after which she collapses from exhaustion. Eventually, Zōsui informs the kunoichi about her being given the chance to enter the Chūnin Exams, with her task being to keep her team-mates replenished. In the Forest of Death, the two genin replenish themselves by biting her, then give her the scroll for safe keeping. Karin gets attacked by a large bear, but is saved by Sasuke.

When she returns from the exams, Zōsui informs her about his disappointment, telling her to go to the "North Fortress", where his allies are fighting the Kaguya Clan. As Karin arrives, she get frightened by the amount of people she is to replenish, fearing that she will die in the process. Some time later, as Karin is attacked by two thugs, the kunoichi is saved by Orochimaru, who invites her to follow him. While in one of the Sannin's hideouts, Karin is welcomed by Kabuto, who asks the kunoichi to showcase her abilities to him first-hand, impressing the medical-nin. In the Northern Hideout, Kabuto informs Karin that she will be helping him out with experiments involving Jūgo. Some time later, Orochimaru recollects with Karin, thanking her for the help and requesting the kunoichi to be in charge of the hideout, to which she humbly accepts. While Kabuto and Karin are talking, Orochimaru and Sasuke stroll though the room, with Karin being informed of the Uchiha. An unspecified amount of time later, Sasuke kills Orochimaru, establishes "Hebi" and fights Killer B and Danzō, where Karin's healing abilities are once again put to use. While in Karin's Infinite Tsukuyomi dream, Sasuke becomes the Sixth Hokage and Konohagakure is attacked by Kusagakure, with Karin being surrounded. Zōsui, who also happens to be there, orders his men to take Karin as a hostage due to her abilities, but the kunoichi is saved and is suggested to have killed Zōsui. Karin, collapsed, is called out by Sasuke, who asks her to wake up, but the kunoichi's only response is a request for him to smile. As Sasuke smiles at Karin, she smiles as well while being trapped in Infinite Tsukuyomi.

Trivia

 * The Kaguya clan is erroneously depicted as still around sometime after the Chūnin Exams in Part I, despite Kimimaro becoming the sole survivor of the clan years beforehand.
 * The development of the Cursed Seal enzyme is also erroneously depicted as having been created after the Chūnin Exams, when it was previously established its creation was during the time Anko Mitarashi was still affiliated with Orochimaru, and it had already been applied to Sasuke and the Sound Five.

Credits
pt-br:Naruto Shippūden - Episódio 431: Aquele Sorriso Novamente