Tanjiro was forcibly injected with Muzan's blood, becoming a demon and losing all his memories (e.g., his family, Nezuko, the Hashira, Inosuke, etc.).

Nezuko was originally a human whose family was murdered, then became a demon who refused to eat humans. Through Tamayo's help, she has become human again.

A user of Water Breathing. He misses Tanjiro and believes he is not disliked by others.

A user of Thunder Breathing. He was always with Tanjiro and misses him dearly. He has a crush on Kamado Nezuko.

A user of Beast Breathing. He was always with Tanjiro and misses him dearly.

The King of Demons (Oni). All demons must obey his commands. He turned Tanjiro into a demon and killed the families of Tanjiro, Giyu, Muichiro, and others.

A user of Wind Breathing. He harbors some hatred toward Tanjiro (though he hates Giyu even more).