Son is a second generation Zainichi Korean, born in Tosu, Kyushu. When he was 16, he went to California, eventually graduating from the University of California, Berkeley, majoring in economics and computer science. He became very excited about the impact computer technology would have, and invented an electronic translator which Sharp Corporation bought for $1.7 million. He then made nearly as much by installing video consoles he imported from Japan, and installing them in restaurants and dorms.

Son also invested in the early days of both Yahoo! and Alibaba, and founded SoftBank, the mobile telecom and investment company, which in 2013 bought Sprint Nextel for $22 billion, but suffered a reported $6.45 billion loss in 22019 as a result of the WeWork IPO collapse.

Recently, Son has become very much involved at the forefront of Solar energy in both japan and Saudi Arabia.