More than two decades ago, South Korea was attacked by a colossal mechanical monstrosity that rose from the depths of the East China Sea. The massive, lumbering construct caused catastrophic damage to coastal cities before it was driven back beneath the waves. In response, the South Korean government developed a mechanized armored drone unit, called MEKA, to protect urban environments in future engagements with the omnic threat.

The government's fears proved to be well founded, as a disturbing pattern of attacks emerged. Every few years, the monstrosity would rise from the sea to assault South Korea and its neighbors. The threat learned from these encounters, often reconfiguring itself in a different form and appearing with new weapons and capabilities. Each incident ended in a stalemate, with the monstrosity defeated but not destroyed.

As the threat continued to adapt, it eventually disrupted MEKA's drone-control networks, forcing the military to place pilots in the mechs. Scrambling to find suitable candidates, the government turned to the country's professional gamers, who possessed the necessary reflexes and instincts to operate the mechs' advanced weapons systems. Top stars willingly joined the effort via the nation's compulsory military service, including reigning world champion Hana Song, also known as "D.Va." Famous for her elite skills, D.Va was a fierce competitor who played to win at all costs, and she had a well-earned reputation for showing no mercy to her opponents.

D.Va quickly grew in skill to become MEKA’s top pilot, even streaming combat operations to her adoring fans, but the Gwishin threats’ increasing attacks on South Korea began to take a heavy toll on the MEKA squad. Where MEKA could once count on months of training and downtime between robotic assaults, a sudden attack between predicted intervals forced Hana to repel the Gwishin alone. The media praised D.Va's singlehanded defense of South Korea, though in truth, the superstar was seconds from a real game over. As the Null Sector threat emerged in Korea, D.Va obtained a special dispensation from her commander to join up as one of Overwatch's new guard, assessing the Null Sector threat alongside Cole Cassidy and his latest recruits.