Junior's early development unfolded under the guidance of multiple instructors, each leaving a distinct imprint on his game. He began with Guilherme Carturan before transitioning to Fábio Gaúcho, who shepherded his progression from white belt all the way through to brown. Fábio Gaúcho operated an affiliate of the Almeida JJ team in São Paulo, and within that environment, Junior evolved into one of the most formidable brown belts in the state.
As his talent signaled potential beyond the regional stage, Junior made a deliberate move to seek training commensurate with his ambitions. He joined Alliance headquarters in São Paulo — widely regarded as one of the sport's most dominant squads — coming under the direction of head coach Michael Langhi. The transition proved transformative, providing the infrastructure, competition exposure, and technical refinement necessary to fulfill his potential. On July 3, 2024, that journey through the colored belt ranks culminated when Carlos José Junior received his black belt under the Alliance banner.