MEKA (Mobile Exo-Force of the Korean Army) was originally a drone only unit designed by the South Korean government in response to the Gwisin, a massive omnics that are made from the underwater South China Sea omnium to attack their country.
After many battles with the giant robot, each resulting in a stalemate where it would retreat into the sea, the drones were eventually compromised. In response, the government began using pilots in these armored units, recruiting such heroes as D.Va.
Hana Song a.k.a D.Va, Role: Mech Pilot for (Tokki)
Yuna Lee a.k.a D.Mon, Role: Mech Pilot for Beast
Kyung-soo Han a.k.a King, Role: Mech Pilot for (Singijeon)
Jae-Eun Kwon a.k.a Casino, Role: Mech Pilot for La Princesse Sereine
Seung-Hwa Shi a.k.a Overlord, Role Mech Pilot for Mastermind