"Things You Can't Get Back" (取り戻せないもの, Torimodosenai Mono) is episode 286 of the Naruto: Shippūden anime.
As both duos travel: Naruto Uzumaki and Killer B, A and Tsunade, the Kumo-nin question their Konoha counterparts about the faith that Tsunade had shown in Naruto. Recalling that she had believed in him long before Pain's assault on Konoha because of a bet he had made to her. Remembering a time before she had met Naruto, Tsunade hurried to the next gambling den while Shizune hurried behind her, upon seeing shinobi fly overhead, Tsunade tells Shizune to let it alone. Upon arrival at the den, where Zaji and his cohorts could barely contain their excitement that the Legendary Sucker had arrived with a lot of cash. Elsewhere, the Raikage retrieves one of his wounded subordinates. Amai, while in the town spots Tsunade and reports back to the Raikage who despite Karai's protesting, decides to have the legendary medical-nin heal him. Approaching the Sannin Tsunade flatly refuses because of the bad blood between the two villages, indignant that that they would even dare to approach her in the first place. This encounter ultimately leads up to Tsunade telling the Raikage that if he could defeat her in arm wrestling, she would go with him. As the titanic competition gets under-way, A, realising that he would not win in a match of strength uses speed to win the match. After seeing the state of the patient, she asks that they tell her what had happened so that her treatment was not compromised.