‘Bleach’: Who “Killed” Captain Aizen & Why?

Sōsuke Aizen, as every fan of the series knows, will remain Bleach‘s most notable villain regardless of everyone and anyone that has and will come after him. The former Captain of the 5th Division, Aizen, actually wanted to surpass the Soul King in powers, and that is why he betrayed Soul Society and became a villain. But, while he was the main villain only in the Arrancar Saga, Aizen’s story remained an important factor in Bleach even later. In this story, though, we will go back to the first part of the story, when someone in Soul Society supposedly killed Aizen. His death was, of course, fake, but we will now explain all the circumstances surrounding it and tell you who actually “killed” Aizen in the first place.

Sosuke Aizen was not killed at the beginning of the series. He actually faked his own death so that he could execute his plan more easily. He himself put the blame on Captain Toshiro Hitsugaya, while some other Captains suspected Gin Ichimaru of being his assassin. Some also suspected Ichigo and others, but that was unlikely, as Aizen was too powerful to be killed by them. It finally turned out that Aizen “killed” Aizen, i.e., that he planted a Gigai and faked his own death.

The rest of this article will be about Sosuke Aizen and his supposed death as it happened on the pages of Kubo’s Bleach series. We will introduce you to this whole history and tell you what exactly happened to Aizen, how it influenced the plot of Bleach, and how it also influenced the interpersonal relationship between the members of the Gotei 13. This article will contain some spoilers, so if you’re not fully up-to-date with everything, you have been warned.

Aizen was actually never killed in the series, but his faked death was an important moment in the series

When he was first introduced to the story, Sosuke Aizen was the benevolent Captain of the 5th Division. He seemed to be calm, intelligent, and quite caring; he also seemed to be loved by everyone and was not antagonistic to Ichigo and his group when they broke into Soul Society.

His Lieutenant, Momo Hinamori, had a very high opinion of him. On the other hand, he seemed to be aware that Captain Gin Ichimaru of the 3rd Division was up to something. Aizen was, along with almost all the other notable members of the Gotei 13, introduced during the Ryoka’s invasion of Soul Society, and his story evolved alongside the adventures of Ichigo and his friends in Soul Society while they were on their way to rescue Rukia.

So, what happened? Well, as we’ve said, Aizen was introduced as one of the good guys, and then suddenly, one morning, he was found dead. His bloodied body was found pierced by a Zanpakuto on the wall of a building in the Seireitei. An alarm was raised, and Captain Hitsugaya of the 10th Division initially suspected Ichimaru, but he had nothing to prove his suspicions.

And while the two clashed, a note written by Aizen himself – the handwriting was his, without a doubt – was found, addressed to his Lieutenant, Momo Hinamori. In it, Aizen accused Captain Hitsugaya of killing him, which caused a rift between Toshiro and Momo.

We have to add that the Captains of the Gotei 13 are extremely powerful, and Aizen was one of the more skilled ones. It is exceptionally difficult to kill a Captain of the Gotei 13, which is why Aizen’s death shocked everyone. Although Captain Unohana of the 4th Division suspected some foul play upon inspecting the body, she could not find any additional evidence.

So, with the Ryoka invading and Aizen dead, the Seireitei was in a state of emergency, and the situation was not made easier by the fact that Rukia’s execution was constantly being pushed forward. Initially, there were three principal suspects in Aizen’s murder.

Gin Ichimaru was the first suspect. At the time, little was known about him. He looked suspicious, behaved suspiciously, and even had a brief verbal clash with Aizen; Aizen did not seem to like him and scolded him for his actions, while Ichimaru always seemed to have a threatening aura around him.

Some other Captains were also suspicious of Ichimaru, but no one really had any evidence. Toshiro Hitsugaya was the one who suspected Ichimaru the most, which is also why he clashed with him at one point.

Ironically, Toshiro Hitsugaya was the second suspect in the murder. He was a young boy and was exceptionally talented, plus – he seemed to be very loyal to the Gotei 13. And while he suspected Icihmaru and worried about Momo, the situation changed quickly.

Namely, not long after Aizen’s murder, a note addressed to Momo Hinamori was found. It was sort of a goodbye message from Aizen to Momo, and in it, he said that his murderer was plotting against the Gotei 13 and that he would be killed because he knew too much. To everyone’s surprise, he accused Toshiro Hitsugaya of being his murderer, which is why Momo attacked him at one point.

The third suspects were also the most obvious ones – the Ryoka. Ichigo, Chad, Orihime, and Ishida, as well as Yoruichi, were named as suspects by some of the Captains, but this theory never became too popular.

Namely, while the Ryoka had to be taken care of, no one really thought that they were powerful enough to kill a Captain of the Gotei 13, and at the time, only Yoruichi had that capacity (the others stood no chance at all), but as her former role in the Gotei 13 was unknown at the time, and she was, for a big part of the invasion, thought to be a black male cat, you can understand why no one really suspected them.

So, these were the three main suspects in the case of the murder of Sosuke Aizen, but as it turned out – none of them was guilty. As it soon turned out, Aizen was killed by – Aizen! And no, it wasn’t suicide. Namely, Aizen was soon discovered to be alive, and it was discovered that Gin is his ally.

He used a Gigai, one so good that even Captain Unohana could not recognize it with absolute certainty, and faked his own death so he could operate more frequently. The Ryoka invasion interrupted him, but he quickly adapted. He wrote a fake letter accusing Toshiro of creating a rift between the Captains. He also killed Central 46 and sped up Rukia’s execution because he wanted to get Urahara’s Hogyoku hidden inside Rukia’s body.

His plan was when revealed: he wanted to merge his powers with those of a Hollow and surpass even the Soul King. It turned out that Captain Kaname Tosen of the 9th Division was also his ally, and the three of them soon escaped to Hueco Mundo, where they prepared for a war against Soul Society.