The Demon Slayer Corps plunges into Infinity Castle to defeat Muzan. Shinobu engages in a fierce fight against Doma, the Upper-Rank 2 demon. Poison doesn't work on him, so she finds herself in an intense struggle. Will she be able to defeat the demon who killed her older sister?! Then another demon appears before Zenitsu and blocks his way.

Tanjiro and Tomioka confront Akaza, the Upper-Rank 3 demon. Against Akaza's overwhelming strength, the two find themselves unable to do anything but defend themselves. With the situation looking grim, Tanjiro awakens to the "Transparent World" his father once told him about. Will this new knowledge allow Tanjiro to turn the tables and go on the offensive against Akaza?

The Demon Slayers fight hard to get their blades closes to Muzan's neck! To avenge her family, Kanao must continue to battle Doma head-on, while Iguro and Kanroji find themselves slashing through the shifting rooms of Infinity Castle. Elsewhere, Tokito, Sanemi and Genya come face-to-face with a villain who recognizes Tokito, but Tokito doesn't know him. Who is this powerful adversary?

Mitsuri immediately engages the Upper Rank and tries to behead her with presumably a Love Breathing technique but Nakime reflects the attack with her Blood Demon Art: Castle Manipulation to warp a wooden door in between them two. As Mitsuri's sword makes contact with the wooden door, Nakime manipulates the door to push Mitsuri off the edge in order to fall to her death. As Mitsuri falls, she nosebleeds from embarrassment and the backfire of her arrogance

Obanai: Kanroji!!

Suddenly, Mitsuri was teleported to safety by who? Mitsuri looks at her savior, it was a female demon wearing a sarashi, she had a kanji for Five, she must be Uppermoon 5, Mitsuri backs away and points her sword at the demon

Mitsuri: W-who are you?!