Stories of the Japanese 01260 [Muromachi/Yoshimitsu Period] The Oei Rebellion: The Fate of Ryoshun

Although the Oei Rebellion had ended, there was a long-standing secret struggle regarding the fate of those involved.
While the matter regarding Kamakura Kubo Mitsukane was settled without punishment, the problem arose when information reached the shogunate that "Imagawa Ryoshun seems to have incited Mitsukane." After being dismissed as Kyushu Tandai, Ryoshun had become the shugo of Totomi and half of Suruga, but he harbored strong dissatisfaction that he had only received 1.5 provinces despite leading the pacification of Kyushu, so he had sufficient motive for rebellion. Furthermore, since Suruga is close to Kamakura, he likely had frequent opportunities to meet with Mitsukane.
On January 11, Oei 7 (1400), the shogunate issued an order to Uesugi Norisada to subjugate Imagawa Ryoshun. It is interesting that the order was issued to Uesugi Norisada rather than Kamakura Kubo Ashikaga Mitsukane or Kanto Kanrei Uesugi Tomomune. It appears the shogunate did not trust either the Kamakura Kubo or the Kanto Kanrei.
Norisada, having received the order, did not attempt to defeat Ryoshun for a long time, instead trying to resolve the matter peacefully by advising Ryoshun to surrender. Ryoshun accepted the persuasion and decided to surrender in July.
However, although Ryoshun announced his intention to surrender, he only sent his second son to Kyoto on September 2, and did not show any intention of going to Kyoto himself to explain his actions. Deeming this a lack of sincerity, the shogunate issued a second subjugation order.
In October, Ryoshun finally went to Kyoto himself to apologize for his crimes, and thanks to the pleas for mercy from his nephew Yasunori, Uesugi Norisada, and others, a decision of "no punishment" was finally reached.
However, Ryoshun's tragedy began here. Ryoshun held Totomi and half of Suruga, but Yasunori demanded the other half of Suruga as a reward for pleading for his life. This was an extreme act of betrayal for Ryoshun.
In the first place, Ryoshun had previously ceded half of Suruga to his brother Noriuji's son, Ujiie, out of consideration for his brother Noriuji. Since that Ujiie had passed away, his younger brother Yasunori had inherited that half of Suruga. In other words, Suruga Province was governed half by Ryoshun and half by Yasunori, but that was only due to Ryoshun's kindness.
Despite this, Yasunori brazenly demanded the remaining half, and Ryoshun, in a weak position, could not refuse and ended up ceding it.
Furthermore, Ryoshun ceded the position of Totomi shugo to his adopted son Nakaki and spent the rest of his life in Horikoshi (Izunokuni City, Shizuoka Prefecture). However, after Ryoshun's death, Yasunori negotiated with the shogunate and snatched away Nakaki's position as Totomi shugo as well. Although the details are unclear, he likely requested it on the grounds of the attempted rebellion by the father and son Ryoshun and Nakaki (Nakaki was Ryoshun's younger brother, but they had entered into an adoption agreement).
In this way, Imagawa Yasunori became a shugo daimyo governing the two provinces of Suruga and Totomi by seizing territory from Ryoshun and his family. The fifth-generation descendant of this Yasunori is the famous Imagawa Yoshimoto.