Nightmare Fuel / Weathering With You

• Hodaka’s reasons for running away have at least some hint of darkness in them:
  • The novelization strongly implies that Hodaka was being physically and emotionally abused by his own father (and by some possible extension, his mother as well). But because the film does not specify this, every hint that we’re given at in the movie makes it clear that he was suffering from a terrible life: the bandages on his face, his negative reactions to going back...it all comes off as Nothing Is Scarier.
  • The thought of what Hodaka’s life might have been like had he not met Hina also counts. What’s even worse is that Japan is also infamous for having a high suicide rate... The alternative, as Shinkai suggests in this interview, that he might pull a Joker (2019) and go off the deep end into violent crime is little better.
• The gun might not be something particularily strange to an American, but to a Japanese person or anyone from a country with strict gun regulations like Japan, it's outright terrifying. A teenager found a fully loaded weapon that can be used to kill someone. An adult would be extremely nervous upon seeing that, a teenager would be terrified.
• The use of Body Horror comes into play when Hina reveals to Hodaka the full extent of the damage her power can do to her.
• Had Hodaka not saved his sister, Nagi would have been left all alone. Doubles as a Tear Jerker and Fridge Horror.
• Takai’s mission to send Hodaka home is understandable, but he may or may not be aware of the abusive relationship between the boy and his dad.
• Takai going berserk with his mission to catch Hodaka. While the scene itself is a bit over-the-top with a bit of Soundtrack Dissonance, just the thought of being chased by someone with a gun that's also taking shots at you at every turn is rather unpleasant.
• Hodaka stopping Hina’s sacrifice comes with the pretty clear implication that scores of Tokyo’s citizens might have died during the non-stop rain, considering how bad its condition is by the time he returns 3 years later.