GungHo is busy.

The Japan-based mobile publisher just bought 70 percent of U.S.-based mobile gaming network Playphone, which has over 800 million subscribers, as reported by Serkan Toto. It’s a key deal in the growing mobile-gaming industry, which could reach $20 billion by the end of 2014, and another significant move in the company’s bid for U.S. growth.

GungHo is best know for the mobile hit Puzzle & Dragons, which is a megahit in Japan. However, the puzzle game is also gaining an audience in the West.

The publisher is doing very well. Its revenue hit $1.22 billion between January and September, up 14.4 percent from the same period last year. It expects October 2014 sales to reach $120 million.

The company also recently announced a partnership with 17-Bit, the developer behind Skulls of the Shogun.