The kami variously enshrined at Kasuga (in the city of Nara) constituted initially the ujigami of the pre-eminently powerful Fujiwara clan, many of whom became members of the imperial line. Kasuga eventually became the ujigami of the entire province of Yamato. Kasuga was also the protector of the Hosso lineage of Buddhism. From about the eighth century until the forced dissociation of kami and Buddhas (shinbutsu bunri) in 1868, Kasuga was identified as a composite divinity, Kasuga Daimyojin, whose cult embraced both the Kasuga shrine and the neighbouring Kofukuji Buddhist temple in a single and indivisible shrine-temple complex overseen by the Kofukuji monks. In Kasuga daimyojin the kami were correlated with Buddhist divinities including Kannon, Yakushi and Jizo (see Gongen). The expansion of the many shrines and temples of this cultic centre gave rise to the city of Nara. From its beginnings as a private Fujiwara and then imperial cult, Kasuga became popular from the late Heian period onwards through the construction in its grounds of the Wakamiya shrine and its annual on-matsuri festival which formed part of the Wakamiya Shinto-Buddhist cult and was open to outsiders. Many branch shrines of Kasuga were eventually established. The emblem of the shrine is the deer, herds of which are still kept in the grounds. In pictures Kasuga is represented riding a deer. The pine tree painted on the backdrop of every Noh stage is the pine tree at Kasuga in which the kami manifested in dance. In the sanja takusen oracles Kasuga is associated with Amaterasu and Hachiman.
A Popular Dictionary of Shinto. Brian Bocking.