A really interesting set-up, but I'm fine with leaving this at Volume One. Saitama is seemingly already on the road to self-actualization, and I feel like there were some missed opportunities with his internal development, though they do go into a bit of backstory. But if you like superhero satire, it's got excellent one-shot villains with hilarious origin stories (won't say much except turns out you actually are what you eat) and some good action sequences and humor. I just don't think that even with the unique direction ONE is taking Saitama's development in, I don't think there's enough material for more than three or four volumes, maybe eight with some twists thrown in.