By the time Buddhism reached Japan (mid 6th century AD), the monkey and monkey lore were already common elements in Buddhist legend, art, and iconography. Thereafter, monkey worship in Japan grew greatly in popularity, especially among practitioners of Taoist Kōshin rites introduced from China and among followers of Tendai Shintō-Buddhism, the latter centered around the syncretic Tendai shrine-temple multiplex located at Mt. Hiei (Shiga Prefecture, near Kyoto). Some scholars believe the famous three monkeys — speak no evil, hear no evil, see no evil — originated in Japan in association with Mt. Hiei and the sacred monkey of the Hie Shrine (Hie Jinja 日吉神社; also called Hiyoshi Taisha 日吉大社).

The central deity at Mt. Hiei is Sannō 山王 (lit. Mountain King; also spelled Sannou, Sanno, Sanoo, Sano), an appellation given to all Shintō deities protecting this sacred mountain. Sannō’s messenger (tsukai 使い) is the monkey. The Sannō deity is broadly conceived, for Sannō actually represents three important Buddha (Shaka,Yakushi, and Amida), who in turn represent the three most important Shintō KAMI (deities) of Hie Shrine. These three Kami are Omiya 大宮, Ninomiya 二宮, and Shōshinshi 聖真子. Collectively, there are 21 Sannō deities at Mt. Hiei, each associated with a specific Buddhist counterpart. These manifestations of the Sannō deity are called Hie Sannō Gongen 日吉山王権現 (Mountain King Avatars of Hie Shrine). Moreover, the number three is of tremendous importance in Tendai doctrine. This supports the notion (still contested) that the three-monkey motiforiginated in Japan in association with Mt. Hiei and Tendai Shintō-Buddhism.

Monkey worship in Japan peaked in the Edo Era, but has declined significantly since then. Even so, the legacy of monkey faith is easily spotted in modern Japan. One can still find old stone statues with monkey motifs in many Japanese localities — statues that are weathering away, unprotected from the elements. Photos of these statues are presented on Page Three. Moreover, certain Japanese shrines (Hie Jinja locations nationwide) and temples (Shitennō-ji in Osaka) continue even today to perform theKōshin rites for those who still believe (most are elderly Japanese), andlucky charms featuring the monkey are still easily found at Japanese temples, shrines, and trinket shops. The color RED is often associated with the monkey, for it signifies the dual role of the monkey as protector against disease as well as patron of fertility.