Jodio Joestar is a quiet teenager with a materialistic outlook who lives a life of petty crime in Hawaii.

In childhood, Jodio was diagnosed with possible sociopathy, that is, he would be a psychopath. The diagnosis was made through a test, a list of items, which revealed in Jodio traits such as impulsiveness and a lack of regret or recognition of guilt.[2] He is not interested in studying[3] and his greatest ambition is to become rich.[4]

Jodio started as an "errand boy" (mule) at age 11 [5] something he still does today, simply transporting things from one place to another. Jodio himself says that he carried out his job diligently and was always discreet, not speaking more than necessary, which gave him confidence from others in the criminal world.[5] As a criminal, Jodio is used to stealing vehicles[6] and dealing drugs at school.[3] When things get serious, Jodio acts violently. For example, when a police officer molested his brother, Jodio immediately took out his stand, November Rain, and attacked the police officer and his partner, not only attacking them with his power, but also stomping them in anger[7] and then burning their patrol car to erase any evidence.[8] He probably hides his criminal life from his mother.

Jodio is also aware of the existence of what he calls "mechanisms", general principles that one must follow and that one can exploit to gain an advantage. For example, he explains how the "trust" (as well as popularity) he enjoys among his peers makes him and his family loved, respected, and protected, and contrasts this with a young man who is being mistreated by his peers. [9] Thus, in Jodio's mind, knowing and following these mechanisms could allow him to achieve anything by overcoming any enemy.[4]

Jodio seems to be a very reserved and lonely boy. Other than his family, he appears to have no close friends. In fact, he explicitly states that he does not go to school to make friends.[3] However, he can be quite sociable and popular within his community, as he is seen dancing with other men and flirting with girls.[10] While quiet and alone most of the time, he is prone to violent behavior, such as suddenly yelling at a classmate when he is too insistent on getting drugs in public[11] or attacking police officers when his family is threatened.[7] He is aware of what he says and recognizes that his goal of becoming "filthy rich" may sound arrogant.[12] Jodio has a lot of affection for his family, which manifests as a protective instinct. He explains that he is protecting his mother and securing his social status through his ties to Hawaii's criminal community.[13]