He learned under Tokugoro Ito and was a training partner of the famed Sanpo Toku.
[4] Omori is considered instrumental in the foundation of Brazilian jiu-jitsu by establishing the first Jujitsu school in São Paulo.
He would later instruct another key Brazilian Jiu-Jitsu founder Luiz França.
[5] Geo had an extensive fight history engaging fighters of various styles including capoeira, boxing, and wrestling.
[5] A 1928 issue of The New York Times highlighted one of his fights against a "negro" capoeira fighter, in which Geo Omori won.