AnimeNewsNetwork interview (partial)

"Firstly, I asked myself, "What really is a hero?" Is a hero just someone who has a superpower? That's probably one of the central elements of a hero, but the people who use these superpowers, or people in real life who have done great deeds—did they just simply use the powers? No. I believe everything has a reaction and a counter-reaction. If they had used that kind of extreme power, there was also a price that the person had to pay. What a hero is, ultimately, I think is getting over those prices that they paid. That's what makes them a hero."