In the English press release, gumi explains the first international move:
Recent growth of the mobile social game market in South Korea and gumi’s decision to enter this market follows the November 2011 lifting of a regulatory ban on games in the Apple App Store and Google Android Market in South Korea. gumi Korea Inc is gumi’s first overseas office, and will be lead by Gibon “Peter” Chang, who brings over 10 years of experience in online entertainment and mobile social gaming to the company.
According to Chang, South Korea’s smartphone market is poised to grow by 60% this year.
The plan for gumi Korea is to develop games both for the local and international markets. In Japan, gumi is very successful with its social card battle games on GREE.