The Four-Tails: King of the Sage Monkeys (四尾・仙猿の王, Yonbi: Sen'en no Ō) is chapter 568 of the Naruto manga.
The Four-Tails tosses the Eight-Tails on the ground, and keeps forcing its mouth shut with Naruto in it while the Nine-Tails watches on. Guy wants to save Naruto, but Kakashi points out their own unfortunate situation between two attack fronts: the Six-Tails' corrosive gas and the other jinchūriki's chakra arms. Kakashi creates a shadow clone and slices through the arms, while Guy punches and burns the gas away. The Eight-Tails wraps its tentacles around the Four-Tails, telling it to let go of Naruto. The Eight-Tails tells the Nine-Tails it heard that it helped Naruto against Madara, the Nine-Tails saying it won't wag its tails to help its jinchūriki as easily as the Eight-Tails. The Eight-Tails questions if it doesn't care at all about what happens to Naruto. The Nine-Tails recalls how many shinobi in the past have restrained it and denied it an identity. The Four-Tails closes its mouth. Naruto meets the Four-Tails, bound by chains. It asks if Naruto is there to take its power, and demands to be called by its proper name, making a boisterous introduction. Naruto apologises for not listening to Son Gokū, which impresses it. Naruto and Son Gokū discuss issues of recognition, identity, and existence. The Four-Tails laughs when Naruto says he's jealous of how B and the Eight-Tails are with each other, before seeing Naruto is serious about it. Considering Naruto to be a better sight than Tobi, Son Gokū offers to help Naruto if he can undo the chains that bind it.