Naruto Shippūden: Season 4, Episode 85

4 - 85: The Terrifying Secret

As Kakashi and the others continue to struggle against the Akatsuki duo, Kakuzu reveals that he has not one, but five hearts! In order to kill him, one must take out all five of his hearts. Meanwhile, Shikamaru decides to challenge Hidan alone, and forces him away from his partner.