Yu Yuan Law · Taipei
Outside general counsel for growth-stage and listed companies
Yu Yuan Law is a Taipei corporate practice founded in October 2024 by Allen Sun. The firm focuses on cross-border M&A, venture financing, IP licensing and commercial contracts, working in English and Traditional Chinese across Cayman, Delaware and Taiwan entities.
Allen Sun
Allen Shih-Yuan Sun
Taiwan-qualified attorney, admitted 2018. Before founding Yu Yuan Law, Allen was a Senior Attorney at PwC Legal Taipei (2017–2024), handling cross-border M&A and corporate advisory work, and then Legal Director at Taiwan Bio-Manufacturing Corporation (2024), where he was the company's sole in-house lawyer.
He holds an LL.M. from National Taiwan University and a B.S. (magna cum laude) and M.S. in mechanical engineering from UCLA. He worked as a mechanical engineer in the U.S. energy industry before practising law and holds a California EIT certification.
Practice Areas
What the firm does
Cross-border M&A
Due diligence, deal structuring, SPAs and pre-IPO restructurings involving Taiwan, Cayman and Delaware entities.
Venture financing
Term sheets, SAFEs, convertible notes, SPAs and SHAs from seed through late stage, for companies and investors.
IP licensing
Licensing, co-development, CDMO/CMO and confidentiality agreements, with an engineer's reading of the technical terms.
Contracts & disputes
MSAs, supply and distribution agreements, employment contracts, and commercial disputes.
Retainer Plans
Fixed weekly hours, fixed monthly fee
Three plans at 2, 5 or 10 consultation hours per week, covering contract review, drafting, deal-structure discussions and day-to-day legal questions. Hours are tallied monthly and reported; unused hours do not roll over. Litigation and standalone transactions are quoted separately at the retainer client's agreed rate.
Every engagement starts with a conflict check and a signed engagement letter. Submitting the form does not create an attorney-client relationship.
hrs / week
Starter
hrs / week
Growth
hrs / week
Dedicated
Insights
Commentary
Short transaction write-ups on the Insight page, and longer commentary on capital markets, cross-border regulation and venture and M&A practice at yylallen.substack.com.