I rambled a bit about this on Twitter, but I want to put this down in a more durable (and slightly longer form). So:

@thatcks: An obvious thesis: I think it matters for Concrete Revolutio that the usual Japanese phrase for 'hero' is apparently 'ally of justice'.

This is 'hero' in the sense of (super)hero, which is what the characters in Concrete Revolutio are. I don't know enough to know if Japanese has a single word that directly maps to this (English) concept, but according to this blog entry on ConRevo translations the Japanese phrase the show uses for this concept is seigi no mikata, which literally means 'ally of justice'.

Continuing from Twitter:

This puts a stronger spin on Concrete Revolutio's constant interrogation of what justice is (and what it means to be its ally).
Characters like Jiro care so much about justice because, well, when they think of themselves as heroes they're literally allies of justice.
If Jiro (or anyone) cannot see what justice is or where it lies, they cannot be the heroes that they want to be and imagine themselves as.

Let me rephrase that to be clearer. When ConRevo's characters think and worry about this, they're of course thinking in their native language, using their native terminology. So when Jiro thinks about being a hero, he literally thinking about being an 'ally of justice', since that's the term and phrase he uses for it. Naturally what you think of yourself as influences what you think about and what your concerns are, so the very term the characters use in ConRevo makes them worry about what justice is (and what it means to be an ally of it). A hero must be 'heroic', whatever that is, but in Western (super)hero works this need not have much to do with justice; however, an 'ally of justice' must be doing things that are on the side of justice, wherever that is. And if you wind up not being on the side of justice, your self-image can fall apart; after all, how can you call yourself an ally of justice any more?

This gives various characters in CR quite strong reasons to cling grimly to their own visions of what justice is, even when it disagrees with other people or leads them to absurd results. I imagine that it also drives characters to want simple, clear definitions that they can follow, instead of messy complicated ones that are very situational and unclear. If you can't see where justice is, how can you know what to do in order to be an ally of justice? Maybe if you act, you're actually working against justice and so being a villain.

This brings me to My Hero Academia and another set of tweets:

A thought: both Concrete Revolutio and My Hero Academia are kind of asking the same question but with totally different viewpoints on it.
And I think that the difference between ConRevo and MHA comes down to the term they use for what it is they're asking about.
In that both ConRevo and MHA are asking 'what is it that makes you a hero/how do you be a hero', but MHA uses 'hero' & CR 'ally of justice'.
So Concrete Revolutio interrogates what justice is, while My Hero Academia asks what is at the core of heroism (vs power & capability).

As far as I can remember from watching it, Boku no Hero Academia consistently used the English 'hero' for what its characters are, not the Japanese 'seigi no mikata' (it even put 'hero' in its Japanese title). One of the clear themes in MHA is that Midoriya (and true heroes in general) are defined by their willingness to act even without the surety of power and conversely that power alone doesn't make you a hero (Bakugo is the poster child of this (also)). Midoriya is not a hero because he has power, he's a hero because he selflessly throws himself into situations to help others who need it (starting with his climactic moment in episode 2).

So, as I see it, both Concrete Revolutio and My Hero Academia have as a theme the question of 'what does it mean to be a hero', except that because they use different terms for it they wind up exploring the question from quite different directions. MHA uses the English 'hero' and winds up approaching it in a way that's very natural to Western audiences. Concrete Revolutio uses the Japanese 'ally of justice' and so winds up exploring the question of what justice is; is it adherence to a law, or to morality, or to the humanity of those you're helping, or what?