About The Arc

The Mount Natagumo Arc is a major storyline in Demon Slayer: Kimetsu no Yaiba where Tanjiro Kamado, Zenitsu Agatsuma, and Inosuke Hashibira battle a deadly family of spider demons on a web-infested mountain. It spans chapters 28–44 in the manga and episodes 15–21 in the anime's first season

The Mission

The trio is dispatched to Mount Natagumo after receiving orders from their Kasugai crows to investigate mysterious disappearances.

The Spider Family

Tanjiro, now a registered Demon Slayer, teams up with fellow slayers Zenitsu and Inosuke to investigate missing person cases on the mountain Natagumo, as noted by IMDb. They discover the mountain is controlled by a dysfunctional family of artificial spider demons led nominally by the Lower Rank Five demon, Rui.

Separation and Survival

The slayers get separated and face extreme danger—Zenitsu is poisoned and fights for his life, Inosuke and Tanjiro face powerful parental spider proxies, and Tanjiro ultimately confronts Rui.

The Main Threat

The primary antagonist of the arc is Rui, a Lower Rank Five spider demon who forces others into a toxic "family" dynamic under threat of death. Tanjiro pushes past his limits against Rui, famously unlocking the Hinokami Kagura (Dance of the Fire God) with Nezuko's help to combat the powerful spider threads.

Intervention of the Hashira

Elite Demon Slayer Corps members Giyu Tomioka and Shinobu Kocho arrive to save the remaining slayers and quickly neutralize the remaining spider family threats.