Cho "Watch" Jae-geol joined NaJin Sword in May of 2012. He played in his first OGN at Azubu The Champions Summer 2012 where his team lost 3-1 to Counter Logic Gaming Europe in the semifinals but beat Azubu Blaze 2-0 in the 3rd place match. Sword earned enough circuit points to qualify for the Season 2 Korea Regional Finals where they ran the whole gauntlet, ending in a 3-2 win against Blaze to qualify for the Season 2 World Championship. At worlds, Sword made it to the quarterfinals but lost 2-0 to the Taipei Assassins. About a month later they attended the 2012 MLG Fall Championship where they met Blaze again in the finals and lost two straight sets, 2-1 and then 2-0.
Sword began the new season at OLYMPUS Champions Winter 2012-2013 where they made it all the way to the finals and beat Azubu Frost 3-0 to win the championship. A few months later, the team attended GIGABYTE StarsWar League Season 2 in China where they placed 3rd after losing 3-0 to Invictus Gaming in the loser's finals. They came back to Korea to participate in OLYMPUS Champions Spring 2013 where they made it to the quarterfinals but lost 3-1 to CJ Entus Frost. After the tournament, Sword and their sister team, Shield, renamed to NaJin Black Sword and NaJin White Shield, respectively. The final OGN of the season was HOT6iX Champions Summer 2013 where Sword had their worst placing yet, failing to make it out of groups. They still acquired enough circuit points to directly qualify for the Season 3 World Championship by taking the first Korean seed. They performed extremely well at worlds, taking the eventual champions, SK Telecom T1, to 5 games in the semifinals but ultimately losing 3-2.
Sword qualified for PANDORA.TV Champions Winter 2013-2014 where they continued their string of poor performances in Champions and dropped out in the group stages again. Following the tournament, watch was moved from Sword to Shield. He played his first tournament with Shield at HOT6iX Champions Spring 2014 where they made the finals but fell 3-1 to Samsung Blue. Next, they attended HOT6iX Champions Summer 2014 and made the quarterfinals but lost 3-2 to the eventual champions, the KT Rolster Arrows. Shield accrued enough circuit points to qualify for the 2014 Season Korea Regional Finals. Amazingly, watch managed to fight through the whole gauntlet again with a different team, culminating in a 3-1 victory against SK Telecom T1 K. They earned themselves the final Korean seed for the 2014 Season World Championship and made it to the quarterfinals but were swept 3-0 by OMG.
With the changes to the OGN rules, Sword and Shield were forced to merge to form NaJin e-mFire. With Sword's jungler, Lee departing from the organization, watch was given the sole starting jungle position. Halfway through SBENU Champions Spring 2015, Peanut became an official sub and was sharing the starting position with watch. NaJin's poor performance in Champions ended with them missing the playoffs and taking sixth. 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. 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. Watch did not play in this tournament. Watch left NaJin in November and joined ZTR Gaming in China in December.