Jirōbō

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

Personality
He dislikes it when Tayuya uses foul language or when she calls him "fat", and he always criticizes her when she does. Despite this, he proceeded to call Choji fat near-constantly during their battle.

Konoha Invasion arc
Jirobo makes a very short appearence here after Orochimaru takes the Third Hokage along with Sakon and Ukon, Tayuya, and Kidomaru. He is seen using a special barrier technique with the rest of the Sound Four to prevent the Third Hokage from escaping the battlefield.

Sasuke Retrieval arc
After Team Shikamaru find the Sound Four, Jirobo allows the rest of his group to go ahead of him while he uses a barrier jutsu and the Chakra Absorption Technique combined to trap Team Shikamaru and drain their chakra at the same time. Shikamaru later has a plan to escape the barrier by making a hole where there is least chakra. Hisplan accomplishes but to be turned out that Jirobo was just getting ready.

After Jirobo insults Shikamaru, Choji shows his anger of this by challenging Jirobo to a 1-on-1 fight leaving the rest of Shikamaru's group to go ahead. Choji takes his first pill and as the fight goes on, he is eventually forced to take the last pill which forces death to occur. Jirobo at some time in the fight activates his cursed seal. Choji easily defeats him with one last punch and eventually kills him.

Abilities
His fighting style consists mostly of basic physical strikes supplemented with the ability to use his chakra to hold the earth solid. His physical strength is unbelievable, which is demonstrated when he holds up a mountain-sized Choji Akimichi when in Level 2 cursed seal form. He tears boulder-sized chunks of dirt out of the ground to throw, creates barriers by tearing up massive sheets of rock, and can drain chakra with his Chakra Absorption Technique. When in Level 2 cursed seal form, his skin becomes red, his mohawk becomes a mane down his back, his eyes turn black, and he gains ten times his normal strength. It is mentioned various time in the anime that he is almost always enormously hungry, and he can get the same energy from absorbing opponents' chakra that one would get from food, as well as vice versa.