Coincheck Signs Business Alliance with KDDI, Forms New Joint Venture

Coincheck Inc., operator of Japan's top-ranked crypto trading app by active users and downloads, has completed a business alliance agreement with telecom and fintech giant KDDI Corp. The two companies, together with au Financial Holdings, have also established a new joint venture to advance a non-custodial wallet business. The new entity, named au Coincheck Digital Assets, was formed in December 2025, according to a joint announcement.

KDDI brings its au ecosystem, including the au PAY mobile payment service with approximately 39.67 million members. Coincheck contributes its expertise as Japan's largest crypto exchange by customer base and a broad lineup of digital asset services. The partnership aims to give au ecosystem users easy access to cryptocurrencies and other digital assets, aligning with Coincheck's mission to make "new value exchange more familiar."

The newly established company, au Coincheck Digital Assets, is headquartered in Minato, Tokyo and will be led by Michihiko Kasai. Its core product is expected to be a non-custodial wallet offered as a mini-app within au PAY. The venture targets a frictionless user experience that combines custody, everyday use, and seamless integration with au services, including au Jibun Bank and Ponta loyalty points.

Non-custodial wallets have faced adoption hurdles due to complex setup and fund transfer requirements. The joint venture seeks to lower these barriers by delivering a wallet that is simple and secure, enabling users to hold and transact crypto and stablecoins within the au ecosystem without leaving the familiar app environment.

Executives from both sides expressed strong commitment. Toshihiko Tachibayashi, deputy head of KDDI's Open Innovation Promotion Division, said the partnership provides a robust framework for next-generation financial services, emphasizing safety and reliability alongside convenience. Tomoyuki Isaka, chief executive officer of Coincheck, highlighted the opportunity to scale value delivery by combining Coincheck's on-chain expertise with KDDI's customer reach.

As a first step, a campaign for customers opening Coincheck accounts through au-related services will be launched shortly, with details to be announced later. The collaboration underscores a broader push to expand crypto and stablecoin adoption in Japan, particularly among mainstream consumers.