Kanku (884 - February 28, 972) was a Shingon sect priest in the middle of the Heian period. His secular surname was the Bunya clan. It is said that he was from Kyoto or Kawachi Province, but it is not certain. He is also called Rendaiji Sojo or Koryuji Sojo.
He worked as jido (a page) for the Emperor Uda and then became a priest, and learned the method in esoteric Buddhism from cloistered emperor and Jinnichi. Kanku became Gon-Risshi (generally in Shingon sect, fifteenth-ranking Buddhist priest, literally, "supernumerary master of discipline") in 945, and then successively held the following posts; To-ji choja, Kongobuji Temple's zasu (head priest), Ninna-ji Temple betto (secretary in the office of temple), and Ninna-ji temple homu (Director of Temple Affairs) and became Sojo in 964. He established Jobonrendai-ji Temple, and in 971 resigning from all the posts, and he adjusted the temple, which became Koryu-ji Temple by Emperor Murakami's order. He learned Kujaku Kyobo (the ritual for averting disasters, particularly in prayers for rain, against illness in the imperial family, and for safe childbirth of the empress) eight times in his life, and he was known by his miraculous efficacy in the methods of esoteric Buddhism. In 972, he entered nirvana at the age of 89.