There's this one trope that happens in like... every shounen manga that drives me up the wall...
The characters arrive at a new town, and in this town is a bratty little boy who greets our heroes by shouting "I HATE ALL [WHATEVER THE CHARACTERS ARE ie. ninjas/alchemists/superheroes/pirates etc.]! Then probably like... kicks the main hero and runs away. Then I sigh because oh geez, not this bloody plot AGAIN. The heroes go talk to an older sisterly female character who lives in the village, who explains that the boy's parents died either because a [whatever the hero is] failed to stop them from dying heroically to save the village OR they were also a [whatever the hero is] who died heroically saving the village, leaving them all alone! But then a BAD GUY attacks the village and kicks a puppy and is bad, and the boy tries to stop them and then predictably the hero appears just as the bad guy is trying to injure the kid and shields them with their body, getting injured! Then they fight and defeat the bad guy, and the kid learns that not all [whatevers] are bad and now says he'll grow up to be an even better [whatever] than the hero and possibly kicks him again for good measure, oh what an adorable little scamp!
Every time this plot appears, you know exactly how it's going to go down. It's just such a trite, overused plotline that centres around a kid acting nothing like a real child so much as a cheap drama generating machine. Also at least half the time, the kid is inexplicably also perving on the female characters and it's played as endearing? UGHHH.