Very little is known about his early years, as Kakuzu's partner’s past is still shrouded in mystery. Kakuzu's partner had a very brief visual appearance in the anime, so much so that even his name is not known. Based on the information at hand, he was a rogue shinobi of an unknown village and was affiliated with Akatsuki.

In Kaguya Ōtsutsuki Strikes, Itachi Shinden Book: Light and Darkness Arc, Kakuzu's partner made his on-screen debut. In this arc, it was revealed that at some point, Kakuzu’s partner joined the criminal organization Akatsuki after defecting from an unknown village. He then became Kakuzu's fourth partner in the Akatsuki. In the anime, he was eliminated during a battle with numerous shinobi by Kakuzu, who attacked through him to eliminate other enemy shinobi. Kakuzu then claimed that he was too slow and should have just ducked his attack, when the other Akatsuki members chastised his actions. After his death, Kakuzu stole his heart for his forbidden jutsu.

There isn't much information available regarding Kakuzu's partner's personality due to his lack of appearance and relevant information in the series.

He was shown in the anime as a tall guy, even taller than Kakuzu, with small dark eyes, short brown hair, and a mustache. He was wearing a typical Akatsuki cloak, a dark, high-collared cloak with red clouds on it. He had a big nose, and his face was somewhat wrinkled, indicating his advanced age.

The fact that Kakuzu’s partner was able to join the ranks of Akatsuki, in which every member is a skilled shinobi in a league of their own, goes to show his skills as a shinobi. However, most of his skills are unknown, as he never had much of a role or appearance in the series.

Kakuzu stole his heart, which is yet another instance indicating his strength as Kakuzu only considers using the hearts of exceptional shinobi. In the anime, Kakuzu’s partner was seen using a huge sword during a battle, indicating he was skilled in Kenjutsu, sword fighting techniques.

Q. Who is Kakuzu's Partner in Naruto?

A. Kakuzu's partner is a Naruto series character who first appeared, albeit briefly, in Naruto Shippuden Episode 455, "Moonlit Night." He was a rogue shinobi of an unknown village and also a member of the infamous criminal organization Akatsuki. In the Akatsuki, he was partnered with Kakuzu.

Q. How did Kakuzu's Partner die in Naruto?

A. Kakuzu's partner was killed by Kakuzu when he attacked an enemy shinobi right through him, killing him in the process. Kakuzu later stole his partner’s heart.

Q. Who is Kakuzu in Naruto?

A. Kakuzu was a member of the infamous criminal organization, the Akatsuki, and was a rogue shinobi from Takigakure, also known as the Village Hidden in the Waterfall. Kakuzu played the role of an antagonist in the series.