InuYasha

Season 1, Episode 7

Episode Title: Showdown! Inuyasha vs. Sesshomaru

Air Date: 2000-11-27

Overview:

Kagome is able to pull out the Tetsusaiga. Sesshomaru tries to kill her, and Inuyasha is angered and fights to protect Kagome. His will to protect a human changes the Tetsusaiga into its true form, a fang sword.