These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Viewer Gender Confusion: Sonic. Oddly enough none of the characters seem to have difficulty telling that he's a guy.
The Woobie: Saitama himself. He doesn't really act like one, but it's clear that his story-breaking powers have taken their toll. It's first evidenced in earlier chapters when he reflects on how every fight is boring and how even with his deeds, no one recognizes him. Later on, during his fight with Boros, Boros has a Not So Different moment with Saitama, claiming how he himself was the strongest person on his own planet, to the point he searched the universe for a worthy opponent because he wasn't able to take any pleasure in fighting anymore. His final words to Saitama hit home, when he acknowledges the pain that comes with it and how they couldn't have a proper fight with our hero holding back. Saitama simply walks away without any words and a sad look.