Yuki Hamada

Yuki Hamada is a Japanese technical founder and product executive best known as an early executive at Mercari, Japan's largest consumer marketplace. He first co-founded CyBridge (サイブリッジ) in May 2004 while still a student at Tokyo University of Science's Faculty of Science and Technology, building what became one of Japan's largest tutoring-review services before stepping down in October 2014.

He joined Mercari in November 2014 and, in January 2015, became the company's first executive officer (執行役員). In March 2016 he was appointed Director and Chief Product Officer (CPO), leading the Product Division, and in September 2019 he moved to the role of Director and Chief Innovation Officer (CINO). Over his tenure he helped scale Mercari into a platform with tens of millions of monthly users. He left Mercari in July 2021.

Since then, Hamada has positioned himself as a "builder" who codes his own products (in Rust, Swift, iOS, and React) rather than a pure financier. He was an early director/co-founder-level figure associated with the high-end vacation-home startup NOT A HOTEL (per his own profile) and now runs Enabler, under which he ships a portfolio of products spanning AI, smart home, and fintech — including StayFlow (accommodation management), Koe (voice-to-text), chatweb.ai (an AI terminal for Claude/Gemini), Soluna (a member-owned resort in Hokkaido), bim.house, BANTO, and JiuFlow.

He also serves as an outside director of Reiwa Travel (令和トラベル), the travel startup led by former Mercari colleague, a role announced via the company in its board expansion. Alongside operating roles he invests personally as an angel in seed-stage Japanese startups.

• Invests as an individual angel, typically at seed / early stage, primarily in Japan.
• Draws on deep operator experience in consumer marketplaces and product (Mercari) — favors product-led, engineering-driven teams.
• Active interest areas reflected in what he builds himself: AI/AI agents, fintech, travel & hospitality tech, smart home, and consumer apps.
• His personal motto — *"建てて、残して、いいやつらと"* ("Build things, leave them behind, with good people") — signals a bias toward builders and long-term, craft-oriented founders rather than hype.