Siam Partners

Yasuhiro Oba is the Managing Partner and CEO, leading the investment committee. He founded Siam Partners in 2015 after leaving Unison Capital, where he gained mid-market buyout experience. Tatsuo Kawasaki serves as Partner with a focus on deal origination and operational value-creation planning.

The firm targets the Japanese demographic succession crisis. It acquires majority stakes in profitable small-to-medium enterprises — typically in manufacturing, industrial services, and healthcare — where founder-owners lack heirs or internal successors. Siam Partners then professionalizes management, often installing outside CEOs, and drives operational improvements over a five-to-seven-year hold period.

Siam Partners targets companies with enterprise values between ¥1 billion and ¥10 billion, writing control equity checks. The firm executes management buyouts and founder-succession transactions exclusively. It does not pursue minority growth investments, venture-stage deals, or public-to-private transactions.

The firm's primary focus is domestic Japanese SMEs. It will selectively evaluate cross-border opportunities where a Japanese company has an existing Asian subsidiary or where a deal facilitates a Japanese asset's regional expansion, but the core origination pipeline remains domestic succession situations.

Siam Partners relies on a proprietary origination network built around regional banks, local accounting firms, and industry trade associations. Because the succession-driven sellers are often not running formal auction processes, these relationships allow the firm to engage founders before an asset reaches a broad sale process — functioning as a direct-sourcing intermediary.

Siam Partners II, L.P. closed in October 2021 at ¥27 billion, exceeding its initial ¥20 billion hard cap (per Nikkei Asia, 2021). Prior to that, the firm's debut fund size was not publicly disclosed in detail, though industry reports suggest it was below ¥10 billion.

Based on its transaction history and marketing materials, Siam Partners does not invest in real estate, financial services, or pure-play technology startups. The firm's mandate is concentrated on industrial manufacturing, enterprise services, healthcare, and consumer segments where physical operations and tangible assets underpin value.