In the distant future, humanity has been driven to near-extinction by giant beasts known as Klaxosaurs, forcing the surviving humans to take refuge in massive fortress cities called Plantations. Children raised here are trained to pilot giant mechas known as FranXX—the only weapons known to be effective against the Klaxosaurs—in boy-girl pairs. Bred for the sole purpose of piloting these machines, these children know nothing of the outside world and are only able to prove their existence by defending their race. Hiro, an aspiring FranXX pilot, has lost his motivation and self-confidence after failing an aptitude test. Skipping out on his class' graduation ceremony, Hiro retreats to a forest lake, where he encounters a mysterious girl with two horns growing out of her head. She introduces herself by her codename Zero Two, which is known to belong to an infamous FranXX pilot known as the "Partner Killer." Before Hiro can digest the encounter, the Plantation is rocked by a sudden Klaxosaur attack. Zero Two engages the creature in her FranXX, but it is heavily damaged in the skirmish and crashes near Hiro. Finding her partner dead, Zero Two invites Hiro to pilot the mecha with her, and the duo easily defeats the Klaxosaur in the ensuing fight. With a new partner by his side, Hiro has been given a chance at redemption for his past failures, but at what cost? [Written by MAL Rewrite]

The Abyss—a gaping chasm stretching down into the depths of the earth, filled with mysterious creatures and relics from a time long past. How did it come to be? What lies at the bottom? Countless brave individuals, known as Divers, have sought to solve these mysteries of the Abyss, fearlessly descending into its darkest realms. The best and bravest of the Divers, the White Whistles, are hailed as legends by those who remain on the surface. Riko, daughter of the missing White Whistle Lyza the Annihilator, aspires to become like her mother and explore the furthest reaches of the Abyss. However, just a novice Red Whistle herself, she is only permitted to roam its most upper layer. Even so, Riko has a chance encounter with a mysterious robot with the appearance of an ordinary young boy. She comes to name him Reg, and he has no recollection of the events preceding his discovery. Certain that the technology to create Reg must come from deep within the Abyss, the two decide to venture forth into the chasm to recover his memories and see the bottom of the great pit with their own eyes. However, they know not of the harsh reality that is the true existence of the Abyss. [Written by MAL Rewrite]

According to the Republic of San Magnolia, their ongoing war against the Giadian Empire has no casualties—however, that is mere propaganda. While the silver-haired Alba of the Republic's eighty-five sectors live safely behind protective walls, those of different appearances are interned in a secret eighty-sixth faction. Known within the military as the Eighty-Six, they are forced to fight against the Empire's autonomous Legion under the command of the Republican "Handlers." Vladilena Milizé is assigned to the Spearhead squadron to replace their previous Handler. Shunned by her peers for being a fellow Eighty-Six supporter, she continues to fight against their inhumane discrimination. Shinei Nouzen is the captain of the Spearhead squadron. Infamous for being the sole survivor of every squadron he's been in, he insists on shouldering the names and wishes of his fallen comrades. When the fates of these young souls from two different worlds collide, will it ignite the spark that lights their path to salvation, or will they burn themselves in the flames of despair? [Written by MAL Rewrite]

All of a sudden, they arrived: parasitic aliens that descended upon Earth and quickly infiltrated humanity by burrowing into the brains of vulnerable targets. These insatiable beings acquire full control of their host and are able to morph into a variety of forms in order to feed on unsuspecting prey. Sixteen-year-old high school student Shinichi Izumi falls victim to one of these parasites, but it fails to take over his brain, ending up in his right hand instead. Unable to relocate, the parasite, now named Migi, has no choice but to rely on Shinichi in order to stay alive. Thus, the pair is forced into an uneasy coexistence and must defend themselves from hostile parasites that hope to eradicate this new threat to their species. [Written by MAL Rewrite]