A FRANXX is a mech that has to be controlled by two pilots, usually piloted in boy-girl pairs.

The Klaxosaur's are allies.

The VIRM are the villains.

Zero Two usually flirts on Hiro a lot.

Ichigo seems to have feelings towards Hiro.

Zero Two and Hiro co-pilot the Strelizia FRANXX.

Goro and Ichigo co-pilot of the Delphinium FRANXX.

Mitsuru and Kokoro co-pilot the Genista FRANXX.

Futoshi and Ikuno co-pilot the Chlorophytum FRANXX.

Miku and Zorome co-pilot the Argentea FRANXX.