Adult

Adults (オトナ,Otona) are the grown versions of humanity who reside in plantations. The Adult population resides in tall glittering skyscrapers at all times and rarely walk outside. Giant robots called FRANXX are piloted by children referred to as ‘parasites’, whose sole purpose in life is to protect adult-filled cities against the Klaxosaurs.

Appearance
Each adult usually wears a white headdress which covers their eyes and nose. Their skinis seldom exposed in the air. In Episode 01, a large population of adults from Thirteenth Plantation attended the ceremony. Their clothing is quite standardized (i.e. long garments). Some of them held a binoculars-like instrument during the ceremony.

In Episode 10, Old Man and Old Woman are two adults who live in the Inside City. The Old Woman also chats with Zorome for a while.

History
After the discovery of magma energy in 2025, the development of human civilization accelerated and Dr. FRANXX discovered immortality could be achieved. Initially, only the wealthy could afford this but it later became universally available. By 2035, 70% of the human population became immortal but they lost their procreative abilities. To prevent a population explosion, APE passed a law heavily taxing childbirth among the mortals, causing a drastic decline in the birth rate. Due to an increase of klaxosaur attacks, APE led the proposal and construction of plantations, abandoning Earth’s surface. The immortals living in the cities of the plantations became known as ‘the adults’ by the parasites and were kept segregated from the children.

Episode 01
The adults of Plantation 13 attend the graduation ceremony of Squad 13 and watch the parasites closely as Papa presents his speech. Zorome and Futoshi are amazed that so many adults came to see them.

Episode 10
Zorome gets lost in the city after attending an award ceremony and is rescued by the Old Woman. After chatting, Zorome discovers the Old Woman lives with her partner but has no sense of content with trivial things, such as taste and sound. Zorome senses she is familiar to him but she denies they have met earlier. He asks her if they can be friends but she doesn’t answer as he is returned to Mistilteinn.

Episode 15
A super Lehmann-class klaxosaur smashes into Cerasus and sends a horde of Conrad-class klaxosaurs through the hole. Squad 13 fights against the Conrad-class klaxosaurs and manage to defeat the super Lehmann-class klaxosaur with Strelizia's aid. Before Strelizia can destroy the klaxosaur's core, a large klaxosaur hand emerges from the surface and crushes Cerasus, presumably killing off most of the plantation's adult population.

Episode 21
Papa and the Vice Chairman reveal themselves as the leaders of VIRM and begin consuming the souls of all the remaining adults of the plantations. Only the parasites' caregivers survive as the last immortal adults.