Masayoshi Son, born 11 August 1957 in Tosu, Saga Prefecture, Japan, is the founder, chairman, and CEO of SoftBank Group — and one of the most consequential tech investors in modern history. SoftBank's Vision Fund has invested over $100 billion across hundreds of startups.

The Family's Roots: Korean-Japanese Heritage

The Son family is Zainichi Korean — Koreans who settled in Japan during the colonial era (1910–1945). Masayoshi's grandfather emigrated from Daegu, South Korea, to work in the Japanese coal mines around the 1920s.

His Parents

Father: Mitsunori Son — pachinko parlour and restaurant owner.

Mother: Tama Son — homemaker.

His Siblings

Masayoshi is one of four brothers. His brothers include:

Taizo Son, born 1972 — founder of investment firm Mistletoe and Gungho Online Entertainment.

His Wife: Masami Son

Masami Son, née Ono, is Masayoshi's wife. She and Masayoshi married in 1979 while both were students at UC Berkeley.

Their Children

The couple have two daughters:

Mio Son, born ~1986.

Sae Son, born ~1988.

The Son Family Tree at a Glance

Family Origins: Zainichi Korean (originally from Daegu, South Korea).

Parents: Mitsunori Son (pachinko/restaurant owner); Tama Son (homemaker).

Brothers: One of four; notable is Taizo Son (b. 1972, Mistletoe founder).

Wife: Masami Son née Ono (married 1979).

Children: Mio Son (~1986); Sae Son (~1988).

Masayoshi Son:

  • Born 11 August 1957, Tosu, Saga Prefecture, Japan
  • Took the Korean surname (Son) publicly, not the Japanese-styled Yasumoto used by some Zainichi Koreans
  • Holly Names High School (Oakland); UC Berkeley (BA Economics, 1980)
  • Founded SoftBank in September 1981
  • Bought 35% of Vodafone Japan, renamed SoftBank Mobile (2006)
  • Most famous early investment: $20 million in Alibaba in 2000 (eventually worth over $80 billion)
  • Founded Vision Fund (2017) with Saudi PIF backing
  • Other major investments: Yahoo Japan (founder Japan partner), Sprint, ARM Holdings (acquired 2016), WeWork, Uber, OYO, Cruise, ByteDance

What the Son Family Story Teaches Us

A grandfather who emigrated from Daegu to work in Japanese coal mines. A father who ran pachinko parlours. A Zainichi Korean son who chose to use his Korean surname publicly. A UC Berkeley education on a stipend. A wife met at the same university. Two daughters. A holding company that has invested in some of the most consequential technology companies of the last 25 years.

For every family — large or small, famous or otherwise — the Son story carries the same lesson. Choosing whether to use the heritage name or the assimilated name is itself a meaningful family-tree decision. Many Zainichi Koreans in Japan adopt Japanese-style names; Masayoshi chose to retain Son. Write down the names your family has used over time, and which generations chose which. The names carry stories.

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