Shinsei Bank, a Japanese lender with about ¥10 trillion in assets, said it will begin offering Bitcoin as a rewards option on its credit-card platform. The move marks the first time a major Japanese bank has integrated cryptocurrency incentives into a mainstream consumer payments product. Cardholders will be able to accumulate Bitcoin—and potentially other digital assets—through everyday spending, similar to existing cash-back and points programs. The bank framed the service as part of a broader strategy to diversify customer benefits and keep pace with growing domestic interest in cryptocurrencies.