Kumoi is seen in two outfits. The first is a white kimono with a purple wrap, looking similar to a sweater. The second is the standard Shinigami uniform with a red kimono over it. He has white hair slicked back, large sideburns extending into a large white beard, and one spectacle in his left eye. When smiling, it is noticeable he is missing a few teeth on the right side.
Kumoi often adopts a smiling and benevolent expression in front of public appearances, which belies his evil and cunning nature. He was believed to be power hungry, wanting to take Rurichiyo Kasumiōji's position as the head of the clan, but was later revealed to work for Shūsuke Amagai.
Kumoi is the steward who handles most of the family affairs. However, when Rurichiyo's father passed away due to illness, he had planned to usurp the head family seat, gathering supporters and creating an assassination squad for his own purposes. He has his assassins kill off the clan leaders in the noble family who disagree with his views or discover his plans. His main goal is to kill Rurichiyo, the last true descendant of the Kasumiōji Clan, which he has failed to do on several occasions back in Seireitei.
During an unspecified amount of time before Shūsuke Amagai's rebellion, Kumoi abused the Kasumiōji tradition of creating ceremonial swords in order to advance Bakkōtō research. He ordered that the Bakkōtō be tested on Human subjects. Some of the earlier Bakkōtō proved too demanding for the assassins wielding them to support with their Reiatsu, and the subjects were consumed almost on the spot. Captain-Commander Genryūsai Shigekuni Yamamoto attempted to stop Kumoi's actions, but was prevented from doing so by the Central 46. Yamamoto's pupil Shin'etsu Kisaragi volunteered to find out the truth behind the swords, but was quickly caught by Kumoi and used as a test subject, having a Bakkōtō forced upon him. The Bakkōtō quickly overtakes the Shinigami's mind, but it does not consume him. Gyōkaku then orders the brainwashed Kisaragi to "kill the one who sent you here." Following a duel with Yamamoto, Kisaragi is killed and Yamamoto is forced to cover up his death, as the investigation into Kumoi's actions was forbidden. 
The New Captain Shūsuke Amagai arc (anime only)
Note: Events occurring in this arc are only in the anime and do not constitute canon material.
When Rurichiyo Kasumiōji enters her family compound, Kumoi finds her and orders the family vassals to return her to the palace. Taking advantage of the absence of her bodyguards, he calls Hanza Nukui out of hiding and instructs him to have her killed, but Hanza's assassin is stopped by Ichigo Kurosaki and Captain Kenpachi Zaraki. Kumoi managed to trap Rurichiyo's guards during the excitement, but they quickly broke out.  When asked by Nukui why he allowed Rurichiyo to return to the Human World, Kumoi responds that acting too rashly would draw the wrath of the Gotei 13, which would be disastrous to their plans. Kumoi then sends Hanza and a dozen other assassins to the Human World, each sporting a Bakkōtō, to kill Rurichiyo and anyone who dared to stand in their way. The next day, he is seen installing Shū Kannogi as the head of the Kasumiōji Clan.
The next day, he greets Shū and asks how he is doing. Shū reveals that he has no idea what he is supposed to be doing as head of the Kasumiōji Clan, to which Kumoi tells Shū to leave the family affairs to him. Kumoi then meets with Hanza, revealing his anger over Hanza's failure, though admitting that Ichigo is far stronger then they had anticipated. Hanza then asks for another chance to settle the score with Ichigo and kill the princess, prompting Kumoi to ask to see Hanza's true resolve. Hanza permanently binds himself to his Bakkōtō, Saiga, which drains a large amount of his spirit energy, to which Kumoi, showing his respect for Hanza's resolve, orders him to eliminate both Rurichiyo and Ichigo, however, Hanza asks for additional Bakkōtō for his three subordinates: Genga, Jinnai Dōko, and Ryū Kuzu. Kumoi reminds the three of them that the Bakkōtō are dangerous weapons which absorb the life force of the user, however all three of them are not bothered by this. Kumoi, feeling the ends justify the means, complies and grants the three Bakkōtō of their own.  Despite the power bestowed on the four assassins, Ryū Kuzu is the only one to survive the failed assassination attempt, and reports to Kumoi, demanding Nukui's rank. However, Kumoi refuses to do so, telling Kuzu to get lost as he has outlived his usefulness. Furious, the assassin attacks, but is shortly killed by Makoto Kibune in a single stroke. 
In order to keep Kumoi in line, Rurichiyo agrees to marry Shū. However, Ichigo, Rukia Kuchiki, Kenryū, and Enryū attempt to stop them. Captain Suì-Fēng and the patrol corps corner them, prompting Enryū to release his Zanpakutō in order to give Ichigo an opening to reach Shū and reveal Kumoi's true intentions to Rurichiyo's fiance. Together, Ichigo and Rukia escape, pretending to take him hostage. 
Back at the Kasumiōji Manor, Kumoi has ordered his servants to completely repair all of the damaged walls. He also doubled the number of guards, to make sure the manor is secure. Kumoi is noticeably angered at Suì-Fēng's failure to eliminate Ichigo, and is further frustrated by Kannogi's abduction. However he is confident that, as he still has Rurichiyo, his plans will be successful. 
When Kumoi learns about Yamamoto's decision to invade the Kasumiōji Manor, he becomes angered at how he was "betrayed". He opens the door to a room full of intricately-designed katana blades, saying he is now forced to use them. Later, he receives a status report and tells his guards to buy him time to find the Bakkōtō smithy. Moments later, to his shock he also learns that a Shinigami is present in the manor. Almost immediately afterwards, the barrier around the manor is broken down by Suì-Fēng while several Shinigami enter the building, including Captains Jūshirō Ukitake and Shunsui Kyōraku. Seeing no other choice, Kumoi demands that Rurichiyo be brought to him so he can use her as a shield.
Kumoi arrives with other officials in the manor who speak to him about the situation. When they see Rurichiyo gagged, they demand to know what happened. Kumoi then stabs one of the officials with the sword he is carrying and asks the assassins to dispose of the others. Rurichiyo angrily tells him that he won't live free for killing vassals, but he retorts, saying he is the rightful owner to the house. Kumoi takes her away and threatens to kill her, though Ichigo manages to arrive before he can do anything. Ichigo quickly dispatches the assassins and asks that Rurichiyo be returned back, but Kumoi again threatens her life. Rurichiyo explains his motives to Ichigo, and Rukia and Shū who recently arrived. Kumoi exchanges words with them and attempts to end the princess' life.However, Amagai suddenly appears and halts everyone, causing Kumoi to tense up. When Rurichiyo runs to Ichigo, Amagai points his sword in-between them. Much to everyone's surprise, he then slashes Kumoi. He gathers something from the Bakkōtō and kidnaps Rurichiyo, quickly fleeing the scene. The others are left in total shock, even more so when Kumoi, stating that he had done everything he had been told to do, indirectly reveals that he had collaborated with Amagai.
Powers and Abilities
Master Inventor: Seeing that he invented the Bakkōtō, he is a proficient inventor with the works of Reiatsu.
- ↑ Bleach anime; Episode 189
- ↑ Bleach anime; Episode 173
- ↑ Bleach anime; Episode 174
- ↑ Bleach anime; Episode 175
- ↑ Bleach anime; Episode 178
- ↑ Bleach anime; Episode 181
- ↑ Bleach anime; Episode 182
- ↑ Bleach anime; Episode 186
|Clan Members||Rurichiyo Kasumiōji • Shū Kannogi • Gyōkaku Kumoi|
|Associates||Shūsuke Amagai • Makoto Kibune • Hanza Nukui • Jinnai Dōko • Ryū Kuzu • Genga • Ryūsei Kenzaki • Rusaburō Enkōgawa|
|Related Articles||Bakkōtō • Kasumiōji Conspiracy|
|Manga Canon||Ganju Shiba · Kūkaku Shiba · Yūichi Shibata · Koganehiko · Shiroganehiko · Horiuchi Hironari · Hisana Kuchiki · Kenji Yamashita · Mitsuru Ishino · Sadatomo Saionji · Taichi Miyamoto · Cleric of the Kuchiki House · Wolfman Clan Elder · Ganju's Gang|
|Anime Only||Ran'Tao · Kusajishi Bull's Gang · Rurichiyo Kasumiōji · Shū Kannogi · Sayori · Gyōkaku Kumoi · Hanza Nukui · Jinnai Dōko · Ryū Kuzu · Genga · Mayu · Tōba|
|Game Only||Konoka Suzunami|