S01E06: Tetsusaiga, the Phantom Sword

The muonna makes Inuyasha reveal the location of his father's grave. Sesshomaru removes Inuyasha's right eye (the black pearl) and opens the entrance to the grave. Kagome is angered by Sesshomaru's cruelty. She goes with Inuyasha after Sesshomaru. Inside their father's tomb is a memento of Inuyasha's father, the sword Tetsusaiga.