Darling in the FranXX, Yakusoku no Neverland Recommendations
In both shows, the main cast of characters are younger aged individuals who live in an enclosed environment isolated from the dangers and revelations of the outside world. Both parties are shocked when they eventually find out about the truth regarding the world/universe they live in.
It both has the same sub plot where youngsters were made to believe in something only to find out the shocking truth about the ones they trust.
If you liked the flashback episode of Hiro and Zero Two's past, then you will probably find Promised Neverland enjoyable.
flashback episode and Promised Neverland have similar plot and settings, and full of surprises and plot twists(flashback episode not as good and mush surprise and plot twist). Also Promised Neverland is overall a lot better than Darling in the Franxx
Both of them is about living in an enclosed world, following the rules there. However, both eventually find out the truth about this so-called utopia and try to escape or fight against it.
Both universes include separated groups of children (more like teens in the case of darling) in worlds that deceive and manipulate them for various dangerous and disturbing reasons. While Neverland involves the main characters discovering the dark secrets of their world very early on and fighting against it for the whole series, darling keep the main group of characters very much in the dark until the last handful of episodes.
Darling in the Franxx also has the added element of romance, since the characters are older and specifically paired up in opposite gender pairs. The teens are also experienced at fighting gigantic monsters and piloting
kids have no idea what adults do
kids suffer the most
kids get in trouble
these shows have a lot of similar aspects and both are very enjoyable