Why Did Kaneki Join Aogiri Tree?

One of the pivotal moments in the Tokyo Ghoul anime was Ken Kaneki’s joining of the ghoul terrorist organization Aogiri Tree after they kidnapped and brutally tortured him. Naturally, many fans wondered what would drive Kaneki to make such a brash and crazy decision after all he just gone through. It turns out that he had his reasons. But what were they?

The beginning of Kaneki’s heel turn 

During Aogiri Tree’s hunt for Rize, the terrorist group stumbles upon Kaneki at Anteiku and kidnaps him. He’s then handed over to Jason Yamori, who brutally tortures Kaneki until his mental state begins to break down. He suffers an identity crisis, and his ghoul side ends up lashing out, which leads him to kill and cannibalize Jason. Afterward, Kaneki decides to leave Anteiku and join Aogiri Tree, stunning both the members of Anteiku and Tokyo Ghoul fans alike. 

Why did Kaneki join Aogiri Tree?

As Jason was torturing him, Kaneki concluded that not having enough power kept him from protecting the ones he loved. In order to keep them safe, Kaneki decided to get stronger. He realized that the only way to do that was to join Aogiri Tree. 

With Aogiri Tree, Kaneki would fight stronger enemies like CCG investigators and other high-level ghouls. As a member, his presence drew the attention of CCG investigators away from Anteiku by being active at Aogiri Tree. But there was another incentive that came with being a part of the Aogiri Tree.

With Aogiri Tree, Kaneki could monitor the threat of the organization and eliminate any potential threats to Anteiku. He could also learn more about the organization’s leader, One-Eyed Owl, and find out more about Rize and why she was so important to other ghouls. The members of Anteiku may not have liked it, but it was a smart move.

Does the same thing happen in the manga?

This event was never depicted in the manga. In fact, the entire situation actually played out quite differently outside of the anime. In the Tokyo Ghoul manga, Kaneki did leave Anteiku, but instead of joining Aogiri Tree, he created his own small group alongside Kazuichi Banjo to battle the Aogiri Tree. This “Anti-Aogiri” group is also in the anime, but Kazuichi is the sole leader of that faction while Kaneki joined the Aogiri Tree.