Brothers incident occurred on June 28, 1193, during the Fuji no Makigari hunting event arranged by shogun Minamoto no Yoritomo and prepared by Tokimasa. The Soga brothers, Soga Sukenari and Tokimune assassinated Kudō Suketsune, the killer of their biological father. In Azuma Kagami and Soga Monogatari, after killing Suketsune, Tokimune also attempted to assassinate the shogun Minamoto no Yoritomo, which is interpreted as a result of Tokimasa's secret maneuvers. Tokimasa had entered Suruga Province and Fujino in advance, before Yoritomo, as a preparation for his secret plan. Furthermore, before that, Tokimasa had established a strong relationship with the Soga brothers, and especially with Tokimune, being his guardian during genpuku and bestowing one of the kanji in his name to Tokimune. Hiroyuki Miura, along with many others have debated that it was through Tokimasa's strong relation to the Soga brothers that led Tokimune to attack the shogun. Minamoto shogunate In 1199, Minamoto no Yoritomo died. He was succeeded by his son and heir, Minamoto no Yoriie, who himself was considered a minor at the age of 18. Yoriie was closer with his father-in-law, Hiki Yoshikazu, than he was with his own grandfather, Tokimasa. He despised his mother, his uncles, and the Hōjō family in general. He was thus independent and rash, unlike his father who depended on the Hōjō. In that year, a regency council was created by Tokimasa, Masako, and Yoshitoki. The most powerful person there (not counting the remaining Minamoto members there and the Hōjō) was Kajiwara Kagetoki, the governor of Sagami. Though he was very close with Yoritomo and trusted by Tokimasa, Yoriie disliked him, and he was executed in Suruga by the shogunate army in 1200. Though it is generally accepted that Yoriie was responsible for the order, it is believed that Tokimasa and the Hōjō might have also been behind it since the Hōjō clan did gain the province of Sagami. Tokimasa was made daimyō of Ōmi Province in the same year. Tokimasa's calculations next turned on his grandson's father-in-law, Hiki Yoshikazu, who his grandson listened to more than he listened to his own regent, Tokimasa. Losing all hope of getting either Shogun Yoriie or Yoshikazu on his side, Tokimasa placed his bets with his other grandson, Yoriie's younger brother and Yoritomo's youngest son, Sanetomo. In 1203, the 21-year-old Yoriie became extremely ill and weak, and Tokimasa produced a plan whereby Japan would be divided between