An old demon named Totosai comes asking to see the Tetsusaiga. Claiming to have forged the sword for Inuyasha's father, Totosai begins a series of tests to determine if Inuyasha is worthy of the blade. When Sesshomaru appears, demanding that Totosai forge a new sword for him, Inuyasha must come to Totosai's aid - but not before learning that only by mastering the powerful "Wind Scar" technique can Inuyasha defeat his brother.