Tanjiro Kamado was known for protecting his sister, who was a demon turned by Muzan, but he didn't mind the title too much, though. He did his missions with his friends, Zenitzu and Inosuke, Nezuko following in the box he carried on his back.

Tanjiro was sent on a mission to the mountains by himself to slay so lower class demons .. an order from the head of the demon slay corps.

As he walked with nezuko being carried in the box on his back, he picked up a scent of a demon. He drew his katana, getting in a stance. He walked slowly up the mountain, following the smell until it got worse. Then he saw .. them

A demon was feasting on the body of a human near the trees, their back to Tanjiro .. Tanjiro raised his sword, raising it high, ready to slay the demon but the demon twitched .. it knew he was there