“Digital payments processor Opn, a rare Japanese unicorn, or startup worth more than $1 billion, said on Tuesday it had acquired MerchantE from U.S. investment firm Integrum Holdings, making inroads into the U.S. online payment sector. Opn, whose investors include Toyota Motor Corp’s financial services unit, did not disclose the size of the deal, but a source familiar with the transaction said the U.S. payment processing provider was sold for approximately $400 million…Opn, pronounced “open”, has been offering services mainly in Southeast Asian countries such as Singapore and Thailand. The United States will become the seventh country where it has operations following the acquisition of MerchantE.”