"Side Story Final Story: The Hero of the Sharingan" (外伝最終話:写輪眼の英雄, Gaiden Saishūwa: Sharingan no Eiyū, Viz: Chronicle 6: Sharingan Hero) is chapter 244 of the original Naruto manga.
With his new Sharingan, Kakashi is able to overcome the Chidori's weakness; though the attack is still fast, the Sharingan gives him enough reaction time to avoid counterattacks. He kills Kakkō and returns to Obito's side. With Iwagakure reinforcements incoming, Obito asks Kakashi to take Rin away and protect her from harm. When the cave-in resumes, Kakashi reluctantly complies. Obito dies, regretting that he couldn't spend more time with his team while also regretting the fact that he couldn't tell Rin that he loved her. Kakashi attacks the newly arrived Iwagakure ninja to fulfil his promise, but soon loses consciousness. He awakes some time later to find the enemies dead, having been killed by his master. With Rin safe, they complete their mission by destroying the Kannabi Bridge.