Bluehole Studio is a Korean based developer founded in March 2007, founded by Gang-Seok Kim. They're the sole developer of TERA, a fantasy massively multiplayer online roleplaying game as well as PLAYERUNKNOWNS BATTLEGROUNDS. Their North-American counterpart is En Masse Entertainment.
"We are filled with passion for achieving our vision of becoming the world’s preeminent MMORPG creator. We have teams with skills and talents to make that passion come true. We have people who are not afraid of change and enjoy challenge. Through unwavering belief in our people, we will continue to strive our hardest to develop top-quality games. We’ve done it before, and we will do it again."