Tanjiro Kamado and Nezuko Kamado vs Rui

Tanjiro Kamado and Nezuko Kamado vs Rui was a battle that took place on Natagumo Mountain. It focuses on the battle between Demon Slayer Tanjiro Kamado, and Nezuko Kamado against Lower Rank 5 Rui.

Prologue
Tanjiro tells Lower Rank 5 Rui that he doesn't have a real family bond, only a fake one made out of fear and violence, not love and compassion. This enrages Rui who then attempts to cut Tanjiro to pieces using his Blood Demon Art: Cutting Thread. Tanjiro dodges the steel-like threads to his best efforts. Rui then surrounds Tanjiro with a barrage of threads. Tanjiro closes his eyes, expecting to be cut up, but he was unharmed. Both Tanjiro and Rui are surprised, as its revealed that Nezuko was the one who protected Tanjiro from the threads, while letting her body receive the full cutting force of the threads. Tanjiro screams Nezuko's name in horror, and then he quickly carries her to safety. Rui realizes that the two are siblings. He is shocked that even though they are human and demon, the younger sister still protected the older brother.