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 Sakon and Ukon and Kidomaru, Jirōbō never refered to his enemies and trash. He usually called them scum or weakling.

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 absorb an opponents chakra in stage 2 form of his cursed seal as well as in his normal form.

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. His strength also allowed him to carry heavy objects for longer amounts of time than his friends could as shown when Tayuya hinted this about him when Team Shikamaru caught up to them.

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 trapped within Shikamaru's shadow. After Sakon's brother Ukon attacked Shikamaru and broke the jutsu,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. He then proceeded to drain their chakra. Neji Hyuga discovers this and alerts the others. Kiba Inuzuka and Akamaru try to bust through the wall, but their attempts are ineffective as the wall repairs itself,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 he refuses, explaining that Shikamaru deserves to die for his actions. Shikamaru has no 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.

Naruto Uzumaki and Kiba Inuzuka attack Jirōbō, but he easily repels them both. After he uses some Earth Release techniques, Jirobo catches and tries to kill Shikamaru,but he is saved by Choji. 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 gives Shikamaru some food pills and says he has his secret weapon with him. Jirōbō laughs at this and attacks them saying he is going to finish them off. Choji then eats one his clan's Three Colored Pills which he calls the green spinage pill. This enables him to match Jirobo's strength and throw him against a tree. When Chōji continues to counter his Earth Release techniques, Jirōbō activates level one of his cursed seal to overpower Chōji. He then proceeds to pound Choji continueously while also stating 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,the yellow curry pill,which he uses to do his expansion techniques on Jirobo,beating him back. Jirobo grabs him and throws him into the sky. Choji then uses become a giant and crush Jirōbō.

Jirōbō then advances his cursed seal to its second stage, giving him enough strength to lift the giant Chōji with one hand and knock him into the air. Chōji reverts to his normal size,falls to ground,and is unable to move. Jirōbō grabs him and drains the last of his chakra saying he was going to need it now that he was in the second stage of his curse mark. when he isn't satisfied with what he got he throws Choji and causes a bag of potato chips amongst Chōji's belongings to fall out,which he eats the last one of before continuing 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 takes the last of his three pills before he can. He then dodges and overpowers Jirōbō with ease saying he is now a hundred times stronger than before. 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 saying that is unforgivable and that he will obliterate him. Choji then concentrates all his newly acquired chakra into his left hand for use as one final attack saying to Jirobo that it was worth his whole life. Jirōbō begs him to stop, but Chōji doesn't listen and punches Jirobo in his chest,crushing his heart,and killing him instantly. His body then returns to its normal form,and Jirobo lay defeated in the bottom of the crater Choji made with his attack.

Trivia

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