"A Shinobi's Determination" (忍びの決意, Shinobi no Ketsui) is episode 90 of the Naruto: Shippūden anime.
An Anbu member seemingly manages to locate the general area of Orochimaru's hideout and sends a message to Konoha to notify Tsunade, before eliminating all traces of his body. Shizune receives the letter and gives it to Tsunade, who decides to send Kakashi to investigate. She inquires as to Kakashi's whereabouts, and Shizune tells her that he is most likely with Naruto. Jiraiya enters through her window, telling Tsunade that he had popped in to see what Naruto was up to, and Tsunade fills him in on what he had missed.
At Ramen Ichiraku, Naruto struggles to eat his miso pork ramen with his dominant right arm in a cast and is nearly fed by Sakura, only for Sai to offer to feed him first, angering Naruto. Kakashi enters the restaurant and attempts to feed Naruto as well, much to the latter's irritation. Kakashi notices Naruto's upset mood and reminds him that he cannot use the Wind Release: Rasenshuriken again and that he considers Naruto his equal, and that Naruto would find a way to use much more powerful techniques. As they exit the shop, Naruto is confronted by Konohamaru, who has perfected the Shadow Clone Technique. With his shadow clones, Konohamaru shows Naruto his new Sexy: Girl on Girl Technique. Sakura is incensed by the move and prepares to punch Konohamaru only for Moegi to strike Konohamaru, causing Sakura to laugh over the deja vu of their actions. She then rounds on Naruto, berating him before the pair is interrupted by Jiraiya.
At Orochimaru's hideout, Kabuto brings Guren to the pit where Orochimaru's prisoners are and puts her in charge of monitoring their fight to the death and to ensure that there are some survivors. Inside Orochimaru's chambers, Orochimaru reveals that Guren was to be his candidate for a new body but due to time restraints, he was forced to choose Gen'yūmaru. Orochimaru then reassures a worried Kabuto that Guren is the perfect woman for their upcoming task. Outside, Sasuke is practising his Chidori using the chakra from his Cursed Seal of Heaven. After finishing the technique, he is stunned when he realises he is being watched by a young boy named Yūkimaru. Sasuke tells Yūkimaru to go home, but Yūkimaru tells him that he has no home and asks Sasuke if he has a home, to which the latter claims he does not. Before their conversation can carry any further, Kabuto comes to whisk Yūkimaru away, apologising to Sasuke for the interruption.
In her office, Tsunade assigns Kakashi as the leader of a search team she had chosen to locate Orochimaru's hideout. Kakashi reads the file and tells her that he could not think of a better team for this mission. As he heads towards the front gate, the search team is revealed to be none other than Team 8. Shino tells Kakashi that he will use his parasitic insects to locate the enemies' chakra, after which Kiba states that he and Akamaru would be able to locate their scent; Hinata adds that her Byakugan will ensure that they locate the hideout. However, she mentions the fact that they may run into Sasuke at the hideout and inquires as to why Naruto is not coming along. Shino explains that Naruto would not be able to contain himself, a sentiment Kiba echoes, and Kakashi confirms that Naruto is being kept in the dark about this mission.
At the top near Hokage Rock, Naruto is saddened over the fact that his Rasenshuriken has a self-inflicting drawback. Jiraiya tells him to be proud of it, as he was able to master what even the Fourth Hokage could not, and subsequently tells Naruto that all he needs is more training, offering Naruto another chance to hit the road with him and train. Naruto agrees, but is dismayed when he finds out that Jiraiya is heading to a hot spring first; however, he cheers up instantly when Jiraiya suggests that he may invite Sakura for a dip as well.