Park "TANK" Dan-won joined NaJin e-mFire in February 2015 as a mid lane substitute. He changed his name from "Rain" after realizing there were many other professional players with that name. He shared play time with Ggoong during the second half of SBENU Champions Spring 2015. NaJin performed poorly and ended sixth overall in the regular season. NaJin placed fifth in the regular season of SBENU Champions Summer 2015 and qualified for the playoffs but they lost in the first round 2-1 to the KOO Tigers. However, TANK did not play in any of these games. They earned enough circuit points to make it to the 2015 Season Korea Regional Finals but lost 3-0 in the first round to the Jin Air Green Wings.
NaJin played in the 2015 LoL KeSPA Cup where they lost 2-1 to Rebels Anarchy in the first round. TANK left NaJin in November to join Snake eSports in December.