After the battle with Giyuu and Tanjiro ended with Akaza killing himself to meet Koyuki, his father, and Keizo again, he ended up in a different hell… Vivziepop’s Hell.

Akaza falls through the roof of the Hazbin Hotel, landing face flat onto the floor before sitting up and rubbing his eyes. “Ngh… my head…" Akaza says before looking up, a shocked expression on his face, his mouth wide open. "What the hell?! What is this place?! Where am I?!” He says, standing up in a defensive position.