Male. Lower Rank Five, favored by Muzan. The third child of the siblings. He is the older brother to the younger siblings. While he monitors and cares for the family, he seems to show particular favoritism toward Guest. If family members disobey or try to leave the mountain, he simply kills them. His Blood Demon Art allows him to cut opponents with spider threads, which are hard enough to snap swords. If he mixes in his own blood, the threads turn red and their strength increases significantly. He only uses blood-infused threads when he is extremely angry.

Male. Plays the Father role. Huge and muscular. The father of the children. He is a man of few words who expresses himself through actions and is... quite violent. He is the strongest in the house after Rui and uses violence whenever Eomo, who plays the Mother role, fails to perform her duties properly. His Blood Demon Art is molting; every time he sheds his skin, he becomes stronger and larger.

Female. Plays the Mother role. The mother of the children. She fears Abo, the father. Knowing she'll be in danger if he's told of her failures, she works desperately hard at her role. She uses spider threads from her fingertips to manipulate humans like puppets. If they are no longer needed, she ruthlessly twists their necks to kill them. She refers to humans as "dolls."

Male. Plays the Eldest Brother role. The first child. He has the body of a spider. He is mischievous and mocks anyone who gets into trouble. His Blood Demon Art involves spitting poison from his mouth. His human-faced spiders also inject this poison when they bite. If a human is bitten, they transform into a human-faced spider themselves.

Female. Plays the Older Sister role. The second child. She is very wary of Rui's moods, though she tries not to let it show on the surface. His Blood Demon Art uses spider threads from her palms to trap targets in a cocoon and dissolve them to death.

Opa's subordinates. There are many of them, and they all look like the profile description. They do not appear unless Opa commands or calls for them—not even a single one.