Kumo Oni Ane

Kumo Oni Ane is fearful, self-serving, and willing to deceive others when doing so might protect her. She has little genuine loyalty to the Spider Family and understands that failing to perform her assigned role can result in severe punishment from Rui.

Her fear does not make her harmless. She captures Demon Slayers in cocoons and allows them to be dissolved, and she attempts to manipulate Shinobu Kochou when confronted. She readily invents a sympathetic story about being forced into Rui's service when she believes it might convince Shinobu to spare her.

Her behavior reflects the hierarchy Rui has imposed on the mountain: she victimizes weaker people while remaining terrified of those stronger than herself.

Kumo Oni Ane possesses the enhanced strength, speed, regeneration, and durability typical of demons, but her principal ability involves manipulating thread.

She creates spherical cocoons from thread and uses them to trap Demon Slayers. Once a victim is enclosed, acidic fluid inside the cocoon begins dissolving the body, allowing her to kill immobilized opponents without fighting them directly.

She can manipulate numerous threads across the forest and suspend her cocoons from trees. Her abilities are effective against ordinary Demon Slayers, but she is drastically outmatched by a Hashira.

Kumo Oni Ane operates on Mount Natagumo as one member of Rui's fabricated household. She participates in killing Demon Slayers sent to investigate the mountain and is shown controlling the cocoons in which several Corps members have been trapped.

After the Spider Family begins collapsing under the Demon Slayer assault, she attempts to escape responsibility and survive. Shinobu eventually finds her and initially speaks to her in a friendly manner, prompting Kumo Oni Ane to claim that she has been unwillingly controlled.

Shinobu quickly exposes the lie and offers an extreme form of atonement for the humans the demon has killed. When Kumo Oni Ane attempts to flee, Shinobu uses Insect Breathing and wisteria poison to kill her.

Rui assigns Kumo Oni Ane the role of elder sister and gives her power as part of his artificial family. She fears him intensely because failure to satisfy his expectations can result in torture or replacement.

Kumo Oni Chichi and Kumo Oni Haha occupy the supposed father and mother roles in the same household.

Kumo Oni Ani is assigned the role of her brother. Their relationship, like the rest of the Spider Family, is manufactured rather than biological.

Shinobu Kochou confronts Kumo Oni Ane during the Mount Natagumo operation. Kumo Oni Ane attempts to deceive Shinobu into sparing her, but Shinobu recognizes the lie and kills her with wisteria poison.