Mitsuri Kanroji and Obanai Iguro vs Nakime

Mitsuri Kanroji and Obanai Iguro vs Nakime is a battle that takes place in the Infinity Castle between the Love Hashira Mitsuri Kanroji and Serpent Hashira Obanai Iguro against Upper Rank 4, Nakime. During the end of the fight, Yushiro joins in the fight to aid the two Hashira.

Prologue
While Mitsuri Kanroji and Obanai Iguro wander through the Infinity Castle, Mitsuri comes across a female demon wielding a biwa with a large bachi pick. They both see the kanji for Four on her singular iris and are surprised that Muzan has already replaced Hantengu's position of Upper Rank 4 so soon. Mitsuri comments to herself that Shinobu sacrificed her own life in order to aid Kanao and Inosuke defeat Upper Rank 2, Doma with her being younger as well.

Battle
Obanai attempts to behead Nakime with his Serpent Breathing: Second Form - Venom Fangs of the Narrow Head.

Aftermath
Yushiro takes control of Nakime's vision to shift the rooms in the Infinity Castle outside in order for Muzan to soon be exposed to the sunlight, by covering Nakime's eye with a paper talisman and drilling his fingers into Nakime's skull. Yushiro successfully gets the remaining Demon Slayers and Muzan outside of the castle.