Jirōbō

was the physically strongest member of the Sound Four and the weakest overall, according to the other members of the Sound Four.

Personality
He disliked it when Tayuya used foul language or when she called him "fatso", and complained to her about it. Despite this, he proceeded to call Chōji Akimichi fat near-constantly during their battle. At first Jirōbō appeared as the silent yet slightly irritated member of the group; until the Sasuke Retrieval Arc in which he revealed an overly sarcastic and arrogant persona. Like several other Sound Four, however, he had his own perception of morality, criticizing Shikamaru for what he saw as giving up on Chōji and selling his team-mates out, which led to his demise at the hands of an overly-enraged Chōji. Like the rest of the Sound Five, Jirōbō constantly referred to his enemies as "trash".

Abilities
Jirōbō could drain chakra. He was almost always enormously hungry, and he could get the same energy from absorbing opponents' chakra that one would get from food.

Like the rest of the Sound Four, he had a cursed seal. When in cursed seal level 2 form, his skin became red, his Mohawk became a mane down his back, and he gained ten times his normal strength. Also, by working together, they are skilled in barrier and sealing ninjutsu.

Arhat Fist
Jirōbō was very strong, such that, when in a cursed seal level 2 form, he could lift a mountain-sized Chōji. Much of his strength is refined into the Arhat Fist fighting style. Which combined simple taijutsu strikes with Jirōbō's incredible physical strength to cause massive damage to his opponents. Using this he could manipulate the earth with his strength from creating barriers to lifting massive sheets of rock. Jirōbō was the physically strongest of the Sound Four but the weakest overall according to the other members.

Earth Release
Jirōbō specialized in Earth Release techniques to compliment his physical prowess, such as throwing large chunks of earth or forming a defensive earth wall. He can also form a prison of earth to drain his opponent's chakra.

Konoha Invasion Arc
Jirōbō made his first appearance with the rest of the Sound Four, erecting a barrier to keep others from interfering in Orochimaru's fight with the Third Hokage. He and the rest of the Sound Four later escorted Orochimaru when he fled.

Sasuke Retrieval Arc
The Sound Four escorts Sasuke Uchiha when he decides to join sides with Orochimaru. After the Sasuke Retrieval Team found the Sound Four, Jirōbō allowed the rest of his group to go ahead of him while he used Earth Release Barrier: Earth Prison Dome of Magnificent Nothingness to trap the retrieval team. Their attempts to escape are ineffective, and their attacks become weaker as Jirōbō slowly absorbs their chakra. Team leader Shikamaru Nara offers to give up on Sasuke and sacrifice the other members of his team if Jirōbō will let him go, but Jirōbō refuses, explaining that Shikamaru deserves to die for being weak enough to get caught. Shikamaru has no real interest in forfeiting, and only spoke to Jirōbō to confirm his location. The team focuses their attacks on the area of the dome furthest from Jirōbō - and thus the weakest - and are able to escape.

The retrieval team attacks Jirōbō, but he easily repels them all. He expresses his sympathies that they have a leader as "useless" as Shikamaru and offers to kill them quickly so they won't realize how unfortunate they are. His words prompt Chōji Akimichi to demand he face Jirōbō 1-on-1. He sends the rest of the team away with his promise that he will defeat Jirōbō. Jirōbō questions why Chōji would think he could win or why he would even let the others escape. By taking one of his Three Colored Pills, Chōji is able to match Jirōbō in strength and distract him long enough for his team to get away. When Chōji continues to counter his attacks, Jirōbō activates level one of his cursed seal to over power Chōji. He then observes that Chōji was left behind because he is the weakest member of the team, sacrificed for the others' benefit. Chōji does not believe that and takes a second pill, which he uses to become a giant and crush Jirōbō.

Jirōbō advances his cursed seal to its second stage, giving him enough strength to lift the giant Chōji and toss him aside. Chōji reverts to his normal size, unable to move. Jirōbō finds a bag of potato chips amongst Chōji's belongings, which he eats before continuing what he was saying before: that Chōji is fat, that he is the weakest member of the team, that he has no friends, and that Shikamaru is a terrible leader. He moves to finish off Chōji, but Chōji, having taken the last of his three pills, dodges and over powers Jirōbō with ease. He pins Jirōbō to the ground and tells him that he could forgive the insults made against him or even that Jirōbō ate the last of his food, but that he will not allow anyone to speak poorly of Shikamaru. Jirōbō tries to convince Chōji to stop but Chōji punches him, creating a giant crater and crushing Jirōbō's chest, killing him.

Trivia

 * Jirōbō can be seen during the Konoha Sports festival and the omake of Naruto Shippūden episode 129.