Trias was first introduced to karate while in the Navy during World War II, when he was stationed in the Solomon Islands. In 1944 Robert Trias met Tung Gee Hsing and began training with him. Hsing practiced the Chinese system of Xingyiquan and had reportedly cross-trained with Motobu Chōki in the Okinawan village of Kume Mura several years previously. Later Trias reportedly studied with Hoy Yuan Ping in Singapore in 1944. In addition to these teachers, Trias learned from other martial art teachers, such as Yajui Yamada (judo), Gogen Yamaguchi (Gōjū-ryū), Roy Oshiro (Gōjū-ryū), Yasuhiro Konishi, Makoto Gima (Shotokan, Shitō-ryū), and several others. Both Konishi and Gima served as mentors to Trias instead of in a formal teacher-student relationship.