FRANXX

FRANXX are robot weapons created by Dr. FRANXX to combat Klaxosaurs, usually piloted by children in boy-girl pairs. Those who can pilot FRANXX are called Parasites.

All FRANXX units are at the disposal of APE, the governmental body of this world.

The FRANXXs feature certain similarities to the flowers after which they were named.

FRANXX
FRANXX units are mecha weapons built by Dr. Franxx and under the supervision of APE. They were specifically designed as defense arsenals against the klaxosaurs and are required for fertile male and female pilots to pilot. In order for the Parasites to connect with their FRANXX, each pilot has to first undress, put on a special underwear, and then change into a suit. The Pistil takes over the FRANXX while the Stamen maintains the control manuals. Every damage the FRANXX gets will be shared with the Pistil. When the paracapacity is low, only the female seems to get exhausted while the Stamen does not feel the stress. Therefore, they need to communicate verbally. Moreover, the Parasites connect their "minds" or to some sort of extrasensory level. The surrounding environment and the faces of the participants in the communication can be projected on the walls.

The FRANXX used by Cerasus differ from typical FRANXX as they each have individual and unique designs befitting of their users. This is most likely because Plantation 13's Parasites are considered special experiments. As shown in Episode 6, the other Plantations have identical FRANXX units, suiting their blank-slate personalities. The 9's have custom made FRANXX units. The facial expression of the FRANXX captures the emotion of the Pistil including happy, angry, exciting and sad.

Parasites
Parasites are those who pilot FRANXX, originally developed as the FRANXX could only be used by humans which still have their reproductive functions. In exchange for immortality, humans had lost their abilities to procreate. As such the need for new children was necessary, as they still retained their reproductive organs and their emotions were key to operating the FRANXXs properly. The need for new pilots was solved by Dr. Franxx's research on cloning and as a result, children were created (e.g: Zero Two). These synthetic children will spend their entire childhood in the Garden, "selected" according to their aptitude test results and be given triple-digit codenames in Arabic numerals. The higher the aptitude, the closer the code will be to 000. To increase their capacity levels, they are given Elixir Injections, or medicine containing yellow blood cells from klaxosaurs, but the drug has a 15% survival rate, resulting in a large number of children succumbing to the effects. When they're old enough, they will be discharged and participate in a graduation ceremony then assigned to a specific Plantation.

The female pilot is known as the Pistil while the Stamen is the male pilot. This is a direct reference to the male and female reproduction organs of flowers. Because the Parasites retain reproductive organs, they are capable of biologically reproducing children. However, it is prohibited for a pregnant Pistil to pilot a FRANXX because it could interfere with paracapacity with the Stamen (although Kokoro was able to pilot with Mitsuru without issue during the early stage of her pregnancy) and, although not necessarily required, when a pregnancy occurs, it is strongly recommended to terminate it. The Parasites, due to being raised in isolation and taught nothing beyond what they experience from within their Plantations, know nothing in regards to human sexuality and sentimentality. When they do become aware and engage in such matters, they will be subjected to re-indoctrination or discharged from duty.

The 9's are capable of battling as either Stamen or Pistil, as explained by 9'a to Hiro in Episode 23: DARLING in the FRANXX.

Below are the names of the current Pistils and Stamen of Plantation 13.

Stampede Mode
Stampede Mode (スタンピード・モード) occurs when a pilot loses control of his or her FRANXX. When a FRANXX is controlled by only its Pistil, their negative factor will rise rapidly and the FRANXX will take on a more beast-like appearance. This will negatively affect the Pistil's health if continued for long periods of time.

This phenomenon is first shown with Strelizia. After 081 dies, Zero Two is forced to pilot alone, transforming it into its beast mode. When Mitsuru refuses to fight and Kokoro tries to pilot Genista alone, the lip of Genista's hat opens, revealing sharp metal "teeth" and two orange crosses for eyes appear, making an animal-like face.

Paracapacity
Paracapacity (, Para Kyapashiti) is the numerical value indicating the degree of synchronization between FRANXX pilot and their FRANXX. There are three levels of paracapcity: high, median, and lower range. The higher the paracapacity, better of a successful synchronization between the pilots. If a pair’s paracapacity falls in the lower range, they are given the option of a “partner shuffle”, or switching partners. If one pilot is deemed the cause of the low paracapacity, he or she will be the target of “pruning“, or will be removed from the squad and sent back to the Garden.

FRANXX