In this biography
Quick facts
- Born
- 11 August 1957
- Birthplace
- Tosu, Saga Prefecture, Japan
- Country
- Japan
- Nationality
- Not independently established
- Known for
- Building SoftBank from software distribution into telecommunications and technology investment
- Founded
- Nihon SoftBank, September 1981
- Education
- Economics studies at UC Berkeley; completed in 1980
- Role record
- SoftBank Group chairman and CEO, as recorded 24 June 2026
Why this life matters
His career connects distribution networks, corporate control and investment risk, while the work of the businesses he backs remains collaborative.
Timeline
Key moments
Software distribution
Establishes Nihon SoftBank.
Yahoo Japan
The joint venture launches with Son as its initial president and CEO.
Alibaba investment
SoftBank dates its investment in the Chinese internet business to this year.
Mobile telecommunications
Chairs Vodafone Japan after its acquisition.
Arm acquisition
SoftBank completes the purchase in September.
Vision Fund
The first major closing brings together commitments from SoftBank and outside investors.
Sale agreement terminated
The proposed NVIDIA transaction does not complete.
Arm returns to public trading
SoftBank retains control following the offering.
Student ventures before SoftBank
Son was born in Tosu, Japan, in 1957. Takeo Kikkawa’s business history describes his Korean family background and a move to the United States during his education. He studied economics at the University of California, Berkeley, completing his studies in 1980 before returning to Japan.
His student projects included an electronic translator and arcade-game businesses. Kikkawa’s account draws partly on historian Hiroaki Yamazaki; the two should not be counted as independent witnesses. These early ventures illustrate finding a market and coordinating help, rather than sole invention of later SoftBank technologies.
Building a route between software makers and customers
In September 1981 he established Nihon SoftBank. Its initial trade was distributing packaged personal-computer software. Publishing followed, placing information about computers alongside a business supplying their programs. The name did not originally describe a deposit-taking bank.
Distribution required suppliers, retailers and financing. Kikkawa describes contracts and credit alongside Son’s ambitions. Entrepreneurship here involved a network of commercial relationships, rather than an idea becoming a business without institutional support.
Internet and mobile infrastructure
Yahoo Japan was established in 1996 as a joint venture, initially led by Son. Its portal business was followed by Yahoo! BB broadband services in 2001. SoftBank’s 2026 timeline separately dates its Alibaba investment to 2000, Vodafone Japan acquisition to 2006 and Sprint acquisition to 2013.
These were different routes into technology markets: forming a local partnership, backing another entrepreneur and buying a network operator. An investor’s commitment of capital should not be confused with inventing the software or designing every service supplied by an associated company.
Investment funds and the limits of scale
The first major closing of the SoftBank Vision Fund in May 2017 brought together capital commitments from SoftBank and outside investors. This was a fund structure, rather than a sum of Son’s personal cash; commitments also differ from money already invested in portfolio companies.
The WeWork episode illustrates why the form of an investment matters. SoftBank’s April 2020 notice distinguished its abandoned tender offer for existing shares from funding and credit support supplied to the business. That notice stated SoftBank’s own explanation for the decision; it was not an independent ruling resolving the dispute. A single label such as bailout can conceal these different transactions.
Arm: acquisition, a proposed sale and a public listing
SoftBank completed its purchase of Arm in September 2016.
A later proposed transfer to NVIDIA did not complete: NVIDIA’s February 2022 filing records termination amid regulatory challenges. Arm’s shares returned to public trading in September 2023 while SoftBank retained control. Acquisition, an abandoned sale and a minority public offering are consequently three different changes in the company’s ownership history.
Leadership, risk and an unfinished record
SoftBank’s officer biography dated 24 June 2026 identifies Son as chairman and chief executive of the group and chairman of Arm. TIME’s February 2026 interview describes a renewed concentration on artificial intelligence. These are dated records of leadership and strategy, not forecasts treated as achieved results.
His legacy includes identifying markets early and mobilising large investments, but assessment must also allow for failed transactions and changing plans. The documents behind individual deals offer a firmer basis for understanding that record than a fluctuating personal-wealth ranking. The connected Arm study shows how to read one such sequence step by step.
Quick answers
Frequently asked questions about Masayoshi Son
- Did Masayoshi Son found Arm?
- No. He founded SoftBank. SoftBank acquired Arm in 2016; founding a business and buying control of an existing one are different events.
- Did SoftBank sell Arm to NVIDIA?
- The parties signed a proposed transaction, but the agreement was terminated in February 2022. The 2023 public offering was a separate event.
Keep exploring
Lives connected to this story
- Akio Morita
Compare another Japanese technology business whose international expansion depended on teams, products and commercial relationships.
- Tadashi Yanai
Read the career of another entrepreneur discussed in Kikkawa’s comparative business history.
- Eiji Toyoda
Compare a manufacturing leader’s institutional choices with those of a technology investor.
Sources and further reading
Explore the evidence
These references support the biography and offer further reading. Official records, first-person accounts and independent reporting provide different perspectives; image records document attribution and licensing.
- 1. SoftBank GroupBiography: Masayoshi Son, as of 24 June 2026
Current offices are qualified to the profile’s stated date, 24 June 2026. Country-archive placement is not a separate citizenship determination.
- 2. SoftBank GroupSoftBank Group History
- 3. Takeo Kikkawa / SpringerTadashi Yanai and Masayoshi Son: Exceptional Challenges Undertaken by the Two Risk Takers (2023)
The consulted Son sections are a 2023 synthesis, partly dependent on Yamazaki’s earlier research. The underlying works were not independently inspected.
- 4. SoftBank GroupRecommended Acquisition of ARM by SoftBank, 18 July 2016
- 5. SoftBank GroupCompletion of Acquisition of ARM by SoftBank, 5 September 2016
- 6. NVIDIA / US SECForm 8-K, Item 1.02: termination of the Arm purchase agreement, 8 February 2022
- 7. SoftBank GroupClosing of Arm’s Initial Public Offering, 19 September 2023
- 8. Associated PressArm Holdings shares gain nearly 25% in stock-market debut, 14 September 2023
- 9. TIMEMasayoshi Son, Japan’s Most Notorious Investor, Is Betting Everything on American AI, 24 February 2026
- 10. SoftBank GroupWho We Are, SoftBank Group Report 2026
- 11. SoftBank Corp.On This Day: Yahoo Japan Corporation Established, 31 January 2022
- 12. SoftBank GroupSoftBank Vision Fund’s First Major Closing, 22 May 2017
- 13. SoftBank GroupEnd of WeWork Tender Offer Because Closing Conditions Not Met, 2 April 2020