Takayuki Ono

TAKAYUKI (TAK) ONO represents global companies, boards of directors, and senior executives facing allegations of corporate misconduct. He advises clients in board and special committee investigations, in matters involving the U.S. Department of Justice and the Securities and Exchange Commission, as well as other federal and state agencies, and in high-stakes litigation in courts across the U.S.

Tak provides strategic counsel on investigations, crisis management, regulatory inquiries, and enforcement actions. He leads internal and whistleblower investigations, coordinates crisis responses, manages interactions with federal and state agencies, and represents clients before those agencies. He has extensive cross-border experience navigating multiple forums and legal systems, having led investigations in the U.S., Japan, and across Asia.

When disputes involve U.S. litigation — including securities and consumer class actions and antitrust claims — Tak draws on substantial civil litigation experience to handle them from start to finish. In matters that demand rapid and coordinated strategy, he draws on his background managing expedited discovery, emergency motions, and other critical litigation strategies.

He also advises companies on the strategic and effective use of AI in investigations, litigation, and compliance, and on how these tools shape corporate risk, exposure, and decision-making.

Tak is one of the few Japanese-English bilingual litigators in the United States focused on cross-border litigation, investigations, and enforcement. He frequently represents Japanese companies, their U.S. subsidiaries, and global companies with operations in Japan.

Before joining Sidley, he practiced at another global law firm, representing clients in investigations and litigation involving alleged anticompetitive conduct. Earlier in his career, he worked as a TV news reporter for an ABC-affiliated station, where he conducted investigative reporting. He is also an FAA-certified commercial pilot.

Investigations, Enforcement & Crisis Management

• Representing a global financial services company in connection with a special committee investigation and defending the company in related securities and derivative litigation in federal court in Florida arising from an approximately US$18 billion write-down of an acquired business unit.
• Counseled a Japanese multinational company in crisis management matters and in internal and government investigations concerning allegations of corporate misconduct.
• Led cross-border internal investigations for a global healthcare company involving alleged Foreign Corrupt Practices Act issues.
• Conducted a sensitive internal investigation for a major energy company involving allegations concerning a senior executive.
• Advised on an investigation by the Securities and Exchange Commission involving a public company client of a global accounting firm.
• Counseled a senior executive of a Japanese manufacturing company in multi-agency U.S. investigations involving alleged corporate misconduct.
• Represented a leading healthcare company in a preliminary injunction trial involving antitrust claims brought by the U.S. Department of Justice concerning a proposed transaction.
• Advised clients in a Securities and Exchange Commission whistleblower matter involving allegations against a leading global investment firm.
• Handled civil investigative demands and regulatory inquiries in connection with antitrust matters involving major multinational companies.

High-Stakes Civil Disputes

• Representing a Japanese automaker in multidistrict litigation involving alleged defects in airbag control units and seatbelt systems.
• Representing a global financial institution in separate False Claims Act actions filed on behalf of the States of New York, Illinois, California, and New Jersey involving allegations related to the bank’s rate setting practices.
• Defended a global consumer health company in litigation involving allegations of securities fraud related to disclosures concerning over-the-counter medicine.
• Litigated matters involving a global telecommunications company concerning False Claims Act issues and disputes related to eligibility and reimbursement under federal funding programs.
• Represented a national retailer in high-stakes litigation involving technology-related commercial disputes with operational and financial implications.
• Defended a medical device sterilization company in litigation involving allegations of exposure to hazardous substances.
• Represented a Fortune 50 retail pharmacy and healthcare company in obtaining dismissal of a tortious interference claim in Delaware, later affirmed by the Delaware Supreme Court.

Some of the above matters were handled prior to joining Sidley.

Tak serves on the board of governors of the Japanese American Bar Association (JABA) and is the founder of its Chicago Regional Committee. He is also active with the Japan America Society of Chicago. His leadership in the broader legal community includes serving as chair of the associate board of the Chicago Committee on Minorities in Large Law Firms, after earlier terms as vice chair and secretary/treasurer. He has also served on the board of directors of the Asian American Bar Association of Greater Chicago and is a member of the National Asian Pacific American Bar Association (NAPABA).