Steve Arneil was born in South Africa in 1934. At the age of 10, his family moved to Northern Rhodesia (now Zambia), and he began training in Judo and boxing. His mother made him stop boxing, but he continued studying Judo.
At age 16, he was selected to represent Northern Rhodesia in rugby. By the age of 17, Arneil had earned black belt status in judo, and he had also practiced Kenpo and karate. He moved to Durban, South Africa, for tertiary studies in mechanical engineering.
In Durban, Arneil trained at a judo dojo that also offered karate training. He made a practice of going down to the harbor and asking arriving Japanese people if they practiced karate; if they did, he would invite them to train at the dojo. In 1959, Arneil left South Africa, bound for Southeast Asia.