Izumo mythology
Refers to the body of myths centered on the Izumo region, particularly those involving Susanoo and Ōkuninushi, as distinct from the Yamato-centered myths in the Kojiki and Nihon Shoki.
Izumo mythology includes Susanoo's slaying of the eight-headed serpent Yamata no Orochi.
記紀神話 refers broadly to the myths recorded in the Kojiki and Nihon Shoki, which include both Yamato and Izumo elements, while 出雲系神話 specifically denotes the Izumo-centered cycle.
Compound of 出雲 (Izumo, a region in Shimane Prefecture) + 系 (lineage, system) + 神話 (mythology). The term is a modern scholarly classification.