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.

Over in the Human World, a Senkaimon opens late one night and two men and a girl step out. The girl complains that she is hungry before they carry on. At Karakura High School, Ichigo Kurosaki is informed by Rukia Kuchiki that a group of Hollow have appeared and the two leave to take care of them. Back at the riverbank, the girl complains once more that she is hungry but her guards say that they cannot buy food yet as their Gigai have yet to arrive. The girl wanders off and sees Ichigo battling the Hollow. After trying to order him around, Ichigo tells her to beat it and her guards return, followed by a horde of Hollow. Ichigo initiates his Bankai and swiftly defeats them but the girl and her guards are gone by the time he finishes. Telling Rukia about them, Rukia tries to track them through the Senkaimon. As they work, Kon informs Ichigo he has new neighbors. The new neighbors turn out to be the gilr and her guards from earlier. Ichigo tries to confront them but they will not divulge who they are. Rukia tries to get information from the Urahara Shop but there is no luck there either. The next day, the three of them appear at school as new students, introducing themselves as Rurichiyo, Kenryū and Enryū.

After school that day, Rurichiyo appears smitten with Ichigo, much to the dismay of Kenryū and Enryū. Over at Ichigo's house, Rukia feels Reiatsu coming from next door and after looking, see Kenryū in Shinigami clothing, believing it to be coming from him. However, an intruder then bursts through their roof and Enryū takes off with Rurichiyo. Ichigo and Rukia chase after the intruder and Ichigo attacks but is blinded by the mirror on the intruder's weapon. After they are blinded once more, Rukia figures out the light is doing more than blinding them and warns Ichigo. Rukia says she believes they are dealing with an assassin but is soon injured, leaving the battle to Ichigo. Ichigo closes his eyes and reflects the assassin's light back at him and disarms him. The assassin then tries to flee, causing Ichigo to fire a a Getsuga Tenshō and the assassin dies in the explosion. Afterward, Kenryū explains that Rurichiyo is from the highest noble family other than the Four Great Noble Houses. He explains that a vassal, Gyōkaku Kumoi has ordered many assassination attempts on Rurichiyo's life and that they have fled to the Human World to try to escape these. He requests Ichigo's aid in protecting Rurichiyo.

Early Stages
Now helping Rurichiyo, Ichigo and Rukia take her, Kenryū and Enryū out for a day on the town, going to the arcade and having dinner later. When Ichigo calls her spoiled, she demands for Kenryū and Enryū to tell her the meaning of the word but they keep silent. Angered, Rurichiyo leaves the table and runs out the door. Finding her discarded gigai, they become worried. Walking by herself, Rurichiyo runs into Orihime Inoue. Orihime gets her to realize her air but as she turns to head back, she is confronted by an assassin. Orihime protects Rurichiyo from a few small strikes but her barrier is eventually overwhelmed. Rurichiyo calls for her guards and Kenryū and Enryū promptly come to protect her. Ichigo and Rukia arrive and attack the assassin but the assassin's Bakkōtō makes the fight tough. Kenryū releases his Zanpakutō and temporarily disables the enemies attacks but Ichigo's attack returns the Bakkōtō to its normal state. Ichigo finally manages to stop the assassin but the assassin promptly commits suicide before being questioned. Afterward, Hanza Nukui goes to the battle scene and retrieves the assassin's Bakkōtō. Ichigo is later awakened by Kenryū and Enryū who say that Rurichiyo is gone again.

Back in the Soul Society, Amagai, Kira and Kibune organize a training event for the third division which goes off rather successfully and the division members begin to accept Amagai and Kibune. Later, Kira and Kibune receive a Jigokuchō, alerting them to a situation in the ruins of the old execution grounds. They arrive to find another division member, Shinta, there. They notice that there are many Hollow surrounding them, which have been let out of their cages. Shinta begins to be absorbed by one and Kibune defeats many of the Hollow before he turns and attempts to kill the Hollow absorbing Shinta, killing it along with Shinta. However, Kira stops him. Kibune calls Shinta weak and says he could not fulfill his duty and has no right to live. The two clash and Kibune says Kira was not able to stop the previous captain's defection. As they clash, their Reiatsu frees Shinta and kills the rest of the Hollow. Amagai arrives and makes sure everyone is okay. Looking at the collapsed platform, it is determined that it was rigged to do so and Kira eyes Kibune. At the Kasumiōji compund, Rurichiyo sneaks through unseen. Kumoi confronts Rurichiyo, saying she should return to the compound. Arriving in Soul Society, Ichigo, Rukia, Kenryū and Enryū decide to split up. On her way, Rukia encounters Kenpachi Zaraki who begins to search for Ichigo. Ichigo sees Rurichiyo entering the palace and he runs after her. Ichigo gets past the guards but Rurichiyo refuses to go. She then sees a girl crying who takes her to the outskirts of the area before attacking her. The girl cuts down the guards before revealing herself as one of Kumoi's assassins. However, Kenpachi arrives and cuts him down before he can harm Rurichiyo. Ichigo and Rukia then return to the Human world.