Kim "GuGer" Do-yeop played for SoNiC under the name Kein in the International e-Culture Festival 2013 where they placed last after 2-0 losses to Xenics Storm and Energy Pacemaker.HK.
Kein changed his name to GuGer and joined NaJin White Shield as a sub. He was moved to NaJin Black Sword as a sub in June of that year and played a few games in SK Telecom LTE-A LoL Masters 2014 for the team. He left Black Sword in October to join the Taipei Assassins as their new AD carry in November with the name Lupin.
Lupin's first tournament with the team was IEM Season IX - Taipei where they made it to the finals but lost 3-2 to the yoe Flash Wolves. Back in Taiwan, they ended in second place in the LMS 2015 Spring Season with a record of 17-4. They lost in the second round of LMS 2015 Spring Playoffs 3-0 to Hong Kong Esports. They only made it to fifth place in the LMS 2015 Summer Season and even though the missed the playoffs they still qualified for the next season of LMS. TPA still had enough circuit points to qualify for the 2015 Season Taiwan Regional Finals but they lost in the first round 3-2 to HKE.
Lupin left TPA in November of 2015 to join NaJin e-mFire in December as their new support under the name GuGer again. The team renamed to e-mFire while they searched for a new organization. In February, that organization was found, and they renamed once again to Kongdoo Monster.
During the 2016 LCK Spring Season, Kongdoo Monster went 1-17 in sets, ending in last place. This forced them to play a relegation match against challenger team MVP, who defeated them 3-1 and relegating them to Challengers Korea 2016 Summer.