Naruto Episode 107 -

Episode 107 is widely considered the beginning of the arc. It is a "canon" episode, meaning it follows the original manga's storyline directly and is essential viewing for understanding the characters' motivations before the jump to Naruto Shippuden .

While recuperating in the hospital, Sasuke reflects on his recent encounters with Itachi and his own perceived lack of progress. Seeing Naruto’s rapid growth, particularly after Naruto defeated an enemy that knocked Sasuke out, fuels his insecurity. Naruto Episode 107

The episode highlights Sasuke's descent into darkness as he realizes his "sword to protect bonds" (Chidori) was unable to scratch Itachi, while Naruto's power is rapidly surpassing his own. Episode 107 is widely considered the beginning of the arc