Han was a shinobi from Iwagakure and the jinchūriki of the Five-Tails. He was at some point captured by Akatsuki and had the Five-Tails removed from his body, causing Han's death. Han was possibly one of the jinchūriki that loathed humanity, due to being neglected and hated by his village, as indicated by Akatsuki member Deidara. Han makes a habit of leaving his right hand tucked inside his kimono. He was rather amicable and friendly when he first met Naruto Uzumaki appearing to be a calm and reserved individual, crediting his and fellow jinchūriki's attitudes due to them witnessing how Naruto had been recently treating Kurama. Han is a very tall man, seen as the physically largest jinchūriki, easily standing a head taller than Killer B.
He is also heavily armoured, wearing what is called "Steam Armour" with a furnace on the back that emits steam. He has light brown eyes and his armour extends all the way to the bottom half of his face, covering it up. Underneath the armour covering the bottom half of his face, he wears a white cloth which also covers both sides of his face and the top of his head. Aside from his red armour, he also wears a red kasa conical straw hat over the white cloth and it seems to be composed of the same material of his armour and furnace. He wears his Iwagakure forehead protector on a black cloth, and over his armour, Han wears a black gi, with the sleeves seemingly torn off and black gloves. He also wears what seems to be a bronze-coloured ring around his neck which he wears over his red armour. Also, the armour covering his arms and torso is plated. Han was a powerful shinobi, enough to be reincarnated by Kabuto Yakushi. After his reincarnation and serving as one of Tobi's Six Paths of Pain, Han is seen with both the Sharingan and Rinnegan. Combining the perceptual and predictive abilities of the former with the shared field of vision ability of the latter, allowed Han to use his attacks in a more precise and coordinated fashion as well as react to enemy attacks more efficiently, both individually and in conjunction and with the other jinchūriki. Han's fighting style seemed to revolve around taijutsu. He covered his body in a special armour with a furnace on his back, that stores large amounts of steam, borrowed from Kokuō's Boil Release which boils Han's chakra to the highest temperature. By regulating the amount and pressure of the steam, Han can severely magnify his physical strength and the force behind his taijutsu attacks. The power behind his steam-enhanced strength is enough to send opponents flying away with a single attack. When his normal attacks are not strong enough, he uses the steam to bolster them, taking his opponents by surprise. This was seen when he sent Naruto in his Nine-Tails Chakra Mode flying into Killer B with such force that both were launched across a significant distance in the forest.
As Kokuō's jinchūriki, Han is granted a significant amount of chakra and stamina from the beast. The full extent of his control is unknown, but he could form at least one of the beast's tails upon his reincarnation. Later on, when attacked and immobilised by B's ink clone, Han transformed into his 'Version 2' form to escape being sealed. He was also able to fully transform into Kokuō, while in this state Han displayed strong ramming power, using his horns to heavily wound the Eight-Tails and B as well sending them back a considerable distance. He is also able to utilise chakra arms in his Version 2 form like most other jinchūriki. In preparation for the Fourth Shinobi World War, Han was reincarnated by Kabuto Yakushi to fight against the Allied Shinobi Forces, before being mobilised alongside the other deceased jinchūriki. As dawn broke on the second day of war, it was revealed that Tobi had turned the reincarnated jinchūriki into his own customised Six Paths of Pain, with each having a Rinnegan and Sharingan in place of their left and right eyes respectively. Each jinchūriki also had their respective tailed beast resealed within them and a chakra receiver embedded into their body. Han later travelled together with Tobi, in pursuit of Naruto Uzumaki and Killer B. Encountering their targets, the reincarnated jinchūriki were sent into battle. With the enemy blinded by Fū's technique, Han attacks them directly alongside Yugito Nii, where he clashed with Naruto. When his punch was blocked, he released steam from his armour and overwhelmed Naruto with his strength. However, when this initial assault failed, he, like the others, unleashed the power of their respective tailed beast by materialising the first of its tails. As Naruto tried to destroy the chakra receiver embedded in Rōshi's chest, Han intercepted him with a steam-enhanced kick, sending him hurtling backwards. Incapacitated in the wake of the Eight-Tails' devastating attack, after B's recent transformation, Han was then restrained by the latter's sealing technique. However, before the sealing's completion, he managed to escape by adopting his Version 2 form. Han then assumed his full Five-Tails form and proceeded to gore the Eight-Tails. When the Five-Tails temporarily regained control of itself and tries to attack Tobi, after Kakashi Hatake and Might Guy's intervention, the beast was restrained and forced to revert to Han's Version 2 form. Regrouping with the other reincarnated jinchūriki, Han then charged towards Naruto but was instead intercepted by Kakashi and Guy. Confronting the Konohagakure jōnin, he took advantage of the Six-Tails' Wisdom Wolf Decay bearing down upon the pair, creating multiple chakra arms in preparation to attack them. However, when these are quickly severed by Kakashi, the jinchūriki ready themselves for another attack. As Son Gokū was resealed into the Demonic Statue of the Outer Path, Han was forced to re-enter his full tailed beast form, as Tobi prepared to go all-out. Unleashing a Tailed Beast Ball along with the others, the jinchūriki instead resorted to a direct assault when these attacks are deflected by Naruto, only to then be repelled as the latter adopted his Tailed Beast Mode. In the resulting chaos, Han attempted to gore the Eight-Tails again, but in a complete reversal, finds himself sent reeling. With this, the rival beasts regrouped and prepared a collaborative Tailed Beast Ball, launching it towards their opponents only to have it diverted by an opposing one.