Following his promotion, Kukuk served as an assistant instructor under Rorion Gracie before making a pivotal decision to relocate to the East Coast. At a time when Brazilian Jiu-Jitsu had almost no institutional presence outside Southern California, Kukuk opened several academies in the region, establishing some of the earliest BJJ training environments on the eastern seaboard.
The momentum generated by those gyms set the stage for one of the most consequential partnerships in early American BJJ history. Kukuk brought Renzo Gracie to the United States, and the two established a New York-based academy together, planting a flag for the art in a city that would eventually become one of the world's most active BJJ communities. Their collaboration also produced an instructional series that reached far beyond any single gym — commonly referenced as the Renzo Gracie – Craig Kukuk Brazilian Jiu-Jitsu series, with some sources identifying the formal title as Brazilian Jiu-Jitsu from A to Z, released in 1993. Distributed to an American audience with little to no exposure to the art, the series functioned as a foundational educational resource at a moment when BJJ had virtually no mainstream visibility outside Brazil.
The partnership between Kukuk and Renzo Gracie eventually dissolved in what was described as a bitter falling out. Internet forums of the era speculated that financial disputes surrounding the instructional series were at the root of the separation, though neither party publicly confirmed the cause, and the reasons behind the split have remained largely unaddressed within the BJJ community.