Manga has much more nuanced and completed ending. Really got me through a bad time IRL.

Real meaning I get from it is change of human developmental level in psychoanalysis.

The "boob madness" is like the milk of human kindness in A Christmas Carol by Dickens.

The manga ending was more implied meaning of faith and trust and generosity (everyone sacrificed significant parts of themselves to trust one another). More about maturity and growing up.

It's been a long time since I finished the anime would have to try to remmeber it. It had a few really good parta not in the manga too and I still like the anime a lot more at times. But over all yeah manga ending really shines a lot better, stronger leasons.