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". He was,however,not above showing his idea of pity to his enemies,as shown in his battle against Choji Akimichi.

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. He could also continue to absorb an opponent's chakra in his second stage,despite the difference in his physical characteristics. He was also an extremly powerful Earth Release specialist.

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,they were caught in Shikamaru Nara's shadow. Sakon's brother,Ukon,attacked him from cover,causing the jutsu to be broken. Jirōbō then 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. He then started to drain their chakra. Using his Byakugan,Neji Hyuga discovered this,and alerted the rest of his team. Kiba Inuzuka and Akamaru then tried to break through the wall,but their attempts to escape were ineffective as the wall rebuilt itself,and their attacks became weaker as Jirōbō slowly absorbed their chakra. Team leader Shikamaru Nara offered to give up on Sasuke and sacrifice the other members of his team if Jirōbō would let him go, but Jirōbō refused,explaining that Shikamaru deserved to die for his actions. Shikamaru however had no real interest in forfeiting,and only spoke to Jirōbō to confirm his location. The team focused their attacks on the area of the dome furthest from Jirōbō - and thus the weakest - and are able to escape.

Naruto Uzumaki and Kiba then attacked Jirōbō,but he easily repelled them both. The team then fell back,but Jirobo easily discovered them and,after using an extremly powerful Earth Release technique,caught holt of Shikamaru by his heels. He then attempted to kill Shikamaru,saying to the rest of the team they didn't want to follow a guy like him,but Choji intervened and saved him. Jirobo then expressed his sympathies that they have a leader as "useless" as Shikamaru and offered to kill them quickly so they won't realize how unfortunate they are. His words prompted Chōji Akimichi to demand he face Jirōbō 1-on-1. He then gave Shikamaru some food pills for the team,saying he had his secret weapon with him. Jirobo laughed at this and charged saying he would finish them. Choji then took one of his clan's Three Colored Pills,calling it the green spinage pill,giving him the strength to match Jirobo. He caught Jirobo and sent the rest of the team away with his promise that he will defeat Jirōbō and catch up. Jirōbō then told Choji once he had finally killed him,his friends would be next. Choji responded saying that might be as easy as he thought it would,overpowered Jirobo,and threw him against a tree. When Chōji continued to counter his attacks,Jirōbō activated level one of his cursed seal to overpower Chōji. He started to pound Choji continueously,while saying that Chōji was left behind because he was the weakest member of the team,sacrificed for the others' benefit. Chōji did not believe that and took a second of his Three Colored Pills,calling it the yellow curry pill,giving him immense chakra which he used to expand parts of his body and repel Jirobo. Jirobo then caught him and threw him in the air. Choji then became a giant and attempted to crush Jirōbō.

Jirōbō advanced his cursed seal to its second stage,giving him enough strength to lift the giant Chōji and knock him into the air. Chōji reverted to his normal size,fell to the ground,and was unable to move. Jirōbō then drained the last of his chakra,saying he would need now that he was in his second stage of his cursed seal. When he was not satisfied with what he got,he threw Choji down,causing a bag of potato chips amongst Chōji's belongings to fall out,which he ate the last one of before repeating what he was saying before: that Chōji is fat,that he is the weakest member of the team,and that he has no friends. He moves to finish off Chōji,but Chōji took the last of his Three Colored Pills,converting all his body's fat reserves into chakra,enabling him dodge Jirobo. He then easily overpowered Jirobo,saying he was now a hundred times stronger than before,and struck Jirobo down. He then tells him he could forgive the insults,and even that he had eaten the last of his food,but that he would obliterate him for what he said about Shikamaru. He then pinned Jirobo to the ground and channeled all his chakra into his left hand,telling Jirobo this last attack was worth his whole life. Jirōbō begged Chōji to stop, but Chōji didn't listen and punched him in the chest,creating a giant crater and crushing Jirōbō's heart,killing him instantly. His body then reverted to its original appearance and he layed defeated in the bottom of the crater Choji had created,leaving Choji the victor of their battle.

Trivia

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