The so-called Chotoku Incident was provoked by an event: Korechika mistakenly believed that Emperor Kazan had trysts with Korechika's beloved third daughter of the late Daijo-daijin (grand minister of state) Kotokuko FUJIWARA no Tamemitsu, whereas in fact the emperor had trysts with the fourth daughter, plotted with his brother Takaie to hide along the emperor's way, and their attendants shot arrows, one of which pierced the emperor's sleeve (according to "Shoyuki" (Diary of FUJIWARA no Sanesuke), two attendants of the retired emperor (Kazan) died).
いわゆる長徳の変は、故太政大臣恒徳公藤原為光の四女に通う花山天皇を、わが思い人為光三女目当てと誤解した伊周が弟隆家と謀って道すがら待ち伏せ、彼らの従者が放った矢が法皇の袖を突き通した一件に発端する（『小右記』によれば、法皇の従者の中に2名の死者が出たとも言う）。