Natagumo Mountain (那な田た蜘ぐ蛛も山やま Natagumo yama?) is a mountain the majority of which is covered with thick trees. The entire place is strewn with numerous cobwebs. The spider family makes their home on the mountain.
When an intruder approaches the Spider family’s tranquil existence on the mountain, the Spider Demon Mother uses her sons to control and murder the invader. Rui, Lower Rank 5 of the Kizuki Twelve and leader of the Spider Family, rules the mountain. Rui ensures that every member of his family does their part to keep the family safe.