 His bow was made of "azusa" wood, specifically the "Betula grossa" or Japanese cherry birch.Since that time, 59 "azusa yumi" (29 vermilion and 30 black - vermilion signifying male energy and black female energy) have been enshrined at the Ise Grand Shrine, Japan's most important Shinto shrine and the main residence of Amaterasu.They serve to protect and purify the shrine's sacred inner chamber.