Any Sci-fi YA novel in the style of Neon Genesis Evangelion?

I’m trying to scratch the itch of Evangelion related media and I wanted to read something relatively similar.

What I look for(Sorry if it’s too specific):

-Young protagonists(between teen and young adult ages).

-Sci-fi with psychological and philosophical aspects in the plot(not necessarily religious)

-If possible kinda “Megalophobia” setting. Where everything happens in a very large scale like very large spaceships or stations/cities, or big battles, etc.

-Big focus on the characters their relationship and if possible some kind of romantic relationship between them that plays a big role in the story.

-The possibility of it being a saga or more than one book so I have time to invest on the characters and how they evolve. (As long as it can be. I’m not worried about spending a whole year reading)

by Kino45