Those bratty kids picking on Kojiro cause he's deaf and (objectively by a varying degree compared to them) smelly is sickening.
It's funny they say kids are innocent and you hear talk of "Oh don't grow up, stay innocent" and all that noise, but kids will always do something mischievous and cruel like bully someone else who's outnumbered or have a quality about them that's easy to make fun of. I hate that.