In 2019, following an uprising in the USA and a subsequent global nuclear war, humanity was decimated by a catastrophe called "The Maelström." A half-century after this cataclysmic event—to preserve humankind—the World Health Organization (WHO) has progressively assimilated worldwide political power and completely redefined society: people are now considered public resources and are guaranteed a happier life. The heightened development of medicine, nanomachine technology, and augmented reality promote this greater devotion to human health. Suffocated by the excessive kindness of Japanese society, high school student Miach Mihie decides to oppose the societal values she considers dehumanizing before the health implant surveillance system WatchMe activates itself the day she turns 18. Miach plans to kill herself with two of her friends, Tuan Kirie and Cian Reikadou. However, Cian betrays the pact in disagreement with Miach's intentions, allowing Tuan to survive her suicide attempt, unlike Miach, who is declared dead. Thirteen years later, now a high-ranking inspector of Helix—an organization affiliated with WHO to monitor military conflicts—Tuan is sent back to Japan after her drug smuggling activities in the Niger warzone are discovered by senior Helix inspector Oscar Stauffenberg. On her first day back to the country she tried running away from, thousands of people simultaneously commit suicide. Tuan is now in charge of investigating this wave of mass suicide and exposing the terrorist organization behind the unprecedented attack.

After unleashing the Death Force machines all over the planet Jerra, Geist has kept himself busy by dismantling them one by one. But now he faces a formidable opponent in the form of Krauser, another M.D.S. (Most Dangerous Soldier) who has aligned himself as the only savior of mankind.

In the distant future, mankind has colonized other planets in the universe. While many planets lived in peace, the planet Jerra has been ravaged by decades of war. Geist is an M.D.S. (Most Dangerous Soldier), an enhanced human with unsurpassed combat capabilities and an insatiable lust for battle. Because of his uncontrollable nature, Geist is cryogenically frozen and locked in a satellite. Several years later, the satellite crashes and Geist wakes up from his sleep to engage in another war. This time, to help the army stop the planet's central computer from activating a doomsday device that will lead to total annihilation of all life on Jerra.

A year has passed since the Star Force returned to save the Earth but another danger now approaches from deep space. A gigantic White Comet hurtles toward our galaxy, obliterating everything in its path. But it is no ordinary comet—it is the deadly Comet Empire, conqueror of worlds... and Earth is the next target! Against orders, the Star Force blasts off to investigate, but even if they can get past the flagship Andromeda, they don't yet know the true nature of their new enemy!