A promising student named Hiro fails to qualify to become a Franxx pilot, but he gets a second chance upon meeting Zero Two, a girl with red horns who loses her Franxx copilot in a monster attack.
Hiro forgets how he and Zero Two won their first battle together, casting doubt on his qualifications as a pilot; the instructors order him to prove himself in a mock battle without Zero Two as his copilot.
Without the confidence of his superiors, Hiro becomes sidelined as his fellow pilots struggle to defend against the monsters while Zero Two embarks with another pilot, Mitsuru.
Doubt surrounds Strelizia's combat readiness after Mitsuru gets badly wounded; those in charge have little choice but to send Strelizia back into battle when another monster appears, and this time Hiro pleads with Zero Two to partner with him again.
It's time for Plantations 13 and 26 to start kissing, and the squad prepares for the huge battle this will cause. They also have to get used to Hiro being Zero Two's partner, and so does he.
A greater threat than any faced before emerges in front of the Franxx squads; Hiro accompanies Zero Two on the mission for his third time and, after giving everything he has to defeat the enemy, Hiro faces the possibility that it will be his last.
Yuto Uemura
Hiro
Haruka Tomatsu
Zero Two
Yuichiro Umehara
Goro
Kana Ichinose
Ichigo
Mutsumi Tamura
Zorome