Morasada was the eldest son of Emperor Reizei. The prince's mother was Fujiwara no Kaneko/Kaishi (藤原懐子), who was a daughter of sesshō Fujiwara no Koretada. Morasada was also the brother of Emperor Sanjō.
Prince Morasada was seventeen years of age at the time of the succession.
He faced a tough political struggle from the Fujiwara family; and at the age of nineteen, he was manipulated into abandoning the throne by Fujiwara no Kaneie. Kaneie told him that Ichijo (Kaneie's maternal grandson) already held the Regalia, and that there was no purpose in Kazan continuing to rule. Under some pressure, Kazan acquiesced, and went to the Gangō-ji monastery. He was accompanied by Kaneie's second son, Michikane, who was also to enter religion. When they arrived, however, Michikane said he would like to see his parents one final time while he was still a layman. Michikane never came back.
Nyūkaku went on various pilgrimages and 're-founded' the Kannon pilgrimage, as a monk to the name of Tokudo Shonin (Some scholars doubt that Kazan, in his unstable mental condition at the time was involved with the founding of the pilgrimage, thereby leaving all of the credit to Shonin) had supposedly already created it. This pilgrimage involved travelling to 33 locations across the eight provinces of the Bando area.
He was told to visit these 33 sites, in order to bring release from suffering, by Kannon Bosatsu in a vision.
It is said that the first site of the pilgrimage was the Sugimoto-dera in Kamakura. This site is also the first site on the Kamakura pilgrimage.
It is suggested by many scholars[who?] that the mental health of Kazan, particularly in later life, was not stable; and therefore, living as a monk may have caused deteriorating behavior.
He is buried amongst the "Seven Imperial Tombs" at Ryōan-ji Temple in Kyoto. The mound which commemorates the Hosokawa Emperor Kazan is today named Kinugasa-yama. The emperor's burial place would have been quite humble in the period after Kazan died. These tombs reached their present state as a result of the 19th century restoration of imperial sepulchers (misasagi) which were ordered by Emperor Meiji.
In general, this elite group included only three to four men at a time. These were hereditary courtiers whose experience and background have brought them to the pinnacle of a life's career. During Kazan's reign, this apex of the Daijō-kan included:
Consort (Nyōgo): Fujiwara no Chōshi (藤原姚子; 971–989), Fujiwara no Asateru's daughter
Consort (Nyōgo): Princess Enshi (婉子女王; 972-998), Imperial Prince Tamehira's daughter
Nakatsukasa (中務), Taira no Sukeyuki's daughter, – Nurse of Emperor Kazan