DARLING in the FRANXX: Blu

Darling in the Franxx (Japanese: ダーリン・イン・ザ・フランキス Hepburn: Dārin In Za Furankisu 2), abbreviated as DarliFra (ダリフラ), is a upcoming Japanese science fiction animated television series co-produced by Trigger and CloverWorks, serving as a sequel to the original anime, where the series takes place where humanity has been driven to endangerment by giant beasts known as klaxosaurs. The remainder of humanity soon establishes military cities known as Plantations, where children are raised to be partnered in boy-girl pairs called Parasites and pilot giant mecha known as FRANXX.

Plot
Blu take place years after the events of the first series where "VIRM", an alien race who once attacked Earth in the past but was defeated by the Klaxosaurs, but returned in the early 21st century as group of scientists known at APE who revolutionary a new energy calling magma energy, with this energy APE sped up the development of human civilization and become immortal but at the cost of losing their reproductive functions. Eventually, the heavy use of magma energy was at the cost of an increasing desertification of the planet leading to the creation of the Plantations containing their own ecosystems and Klaxosaurs who attack the magma energy plants, leading Werner Frank to develop the Franxx with a system of pairing young fertile male and female partners called Parasites was established. The Garden called Mistilteinn was built so that, in isolation, these children could develop the emotional responses required to pilot a Franxx after several failed attempts to complete development of the Franxx units which cost many lives. Many years later, a final battle against the Klaxosaurs.