The time of Team J's formation is unknown. But when they enter the Team Battle Tournament they are already a team, so it's most likely that they've always been a team.
Jacob specializes with Electric type Pokémon.
Julian specializes with Normal type Pokémon.
Jake specializes with Steel type Pokémon.
Jordan specializes with Psychic type Pokémon.
- Originally, Team J was named Team Jacob, but the idea of having a team made up entirely of siblings came.