Kasumiōji Conspiracy

The ''' was a major conflict in which Shūsuke Amagai engineered a plan that utilized the Kasumiōji Clan's Bakkōtō in order to get revenge on Genryūsai Shigekuni Yamamoto for killing his father, Shin'etsu Kisaragi many years ago.

The conflict began with two arrivals, that of Amagai in Seireitei and of Rurichiyo Kasumiōji in the Human World. Amagai, after serving many years in the Patrol Corps, is promoted to the vacant position of Captain of the Third Division. No one is aware that he is not who he seems. In the Human world, the Kasumiōji princess, Rurichiyo, arrives in order to hide from many assassins who are after her life. Once there, she meets Ichigo Kurosaki and friends.

The conflict ended after Amagai was defeated by Ichigo, whereupon he was told of the truth of his father's death. Ashamed at what he has done, Amagai turns to suicide and apologizes for what he has done before being consumed by his own flames.

Prelude
In the Soul Society, Captain-Commander Genryūsai Shigekuni Yamamoto announces that he has approved a new captain for the Third Division and Shūsuke Amagai enters. The division however, is skeptical of him. At their first meeting, Amagai informs Lieutenant Izuru Kira that he would like to have his former teammate Makoto Kibune to take up the third seat position. The third division throws Amagai and Kibune a welcome party. Kirs breaks the tension and Amagai takes a drink of sake, immediately becoming drunk. As the division member take care of Amagai, an emergency is signaled via Jigokuchō. The division heads into the Dangai Precipice World, where there are approximately 30 Gillian. They make quick work of them but are soon confronted by the oncoming cleaner, which has not been deactivated. Suddenly, Amagai appears and defeats the cleaner. Afterward, he praises Kira for taking charge and then falls over, still drunk.