Orochimaru's Test Subject (大蛇丸の実験体, Orochimaru no Jikkentai) is episode 353 of the Naruto: Shippūden anime.
Kakashi stumbles across the hideout for the Iburi clan, who immediately attack him, citing him an an enemy of Orochimaru. As Gottaenters Kakashi's body intent on killing him, Kinoe puts a stop to it, and binds Kakashi with his Wood Release, claiming that he could get intel out of him if he were kept alive. Abandoning the interrogation, Kinoe informs Kakashi that he too was there to get to Orochimaru when he arrived there. Yukimi soon returns and carries Kinoe and Kakashi through a secret passage to the outside world. Leaving Kakashi halfway, Yukimi tells Kinoe of how she dreamt of going outside to where the lovely sounds were coming from. She then enters Kinoe's body after turning into smoke, and the two make their way to the town nearby and partake in the entertainment here. Meanwhile, Kakashi is confronted by an enraged Gotta who demanded to know where Yukimi was before attacking Kakashi. Their intense battle does not last long, as an updraft causes Gotta's unstable smoke body to be torn apart. He passes away quickly, though not before passing on information to Kakashi that caused the young Anbu to immediately seek out the renegade duo. Unveiling his true intentions, Kinoe refuses to sacrifice Yukimi, and opts to run away with Yukimi rather than return to the hollow tree. Elsewhere, the gravely injured Orochimaru finally makes it to the Iburi hideout.