It was after defeating Muzan Kibutsuji. However, Tanjiro became Demon thanks to Muzan. But, Kanao turned him to human.

Kirby: Kanao!!

Elfilin: Kirby, I told you- nevermind...;

Bandana Waddle Dee: Hehe, we did it!!

Everyone was celebrating, until a portal appeared under you, Kirby, Elfilin and Bandana Waddle Dee.

Giyu: Huh?

Sanemi: fainted already

Tanjiro: No, Kirby!!

Kirby: Now it's MHA?!?

Elfilin: If we have next life, then let's play that time