Basically what sold Weathering with You to me is that I really REALLY loved the ending. Sure, Your Name built up their MCs better than Tenki no Ko, and I really thought Tenko no Ko's police chase was basically just action for the sake of action. Still I always did feel Your Name felt off with the super sweet happy ending; it just wasn't like a regular Shinkai movie to me. Sure Tenki no Ko still has a happy ending, at least it's a "sweetbitter" ending which is closer still to the bittersweet endings I'm used to with Shinkai.
Basically, three things happened that will make this more memorable to me than any other Shinkai movie barring Hoshi no Koe (his debut movie) and 5cm/s (which absolutely destroyed me):
1) Sunshine Girl Shenanigans,
2) Hina being younger than Hodaka, and
3) Hodaka sinking Tokyo as a result of his choices
First one I was actually really surprised liking it. Who would have thought a 'superpower' as mundane as making it stop raining for a moment, in just a small part of the city, would be so interesting? The most enjoyable moments in the movie for me was definitely with the part-time job and the SOL stories that came along with it.
Second one was basically a punch in the gut. I honestly truly believed Hina was older than Hodaka, as the previous two movies had the female lead being older. In here, both the MCs looked particularly young, but with Hina acting like the older person and her dub actress really selling it, I thought female lead being older was the same here as the previous two movies. But them revealing Hina hasn't even finished middle school, and here she was not only trying to make ends meet for her and her brother, but also be an emotional support for the runaway Hodaka, and on top of that she was very nearly sold in the sex trade at 15 years old? That was a HOLY FUCKING SHIT moment when Mr. Police Guy with Kuwabara haircut revealed her true age in the police car.
So yeah, first two I probably would forget by the time the next Shinkai movie comes. But the last one? Not in my lifetime. Just like I still vividly remember the bombarded-to-death Earth once the Macross came back, I don't think I'll ever forget the scene of Tokyo underwater due to nonstop rain for 3 years.
Sure, anime talking about the environment isn't new (goodness knows Earth Maiden Arjuna was really preachy about it almost two decades ago), but Tenki no Ko really drives home the message that there is a price to pay for everything. If we take Hodaka as Mankind while Hina as the things Mankind loves to do, then as it is Mankind will definitely harm the world through climate change if it keeps on doing the things it loves. Unlike Arjuna in which they definitely preach "what you doing is BAD!", in here we are shown that
just like it is only logical that Hodaka would want to save Hina, it is only logical that Mankind would still want to keep doing what it loves to do. What Tenki no Ko just wants us to remind us of, is that there EXISTS consequences that we must deal with because of our actions.
Of course, not everything is doom-and-gloom. Even if we are past at the point of no return, Shinkai basically is telling us that humanity will still live on. It might be a different world in the future (like Tokyo being submerged), but hopefully by then we have changed our methods that doing what we love doesn't harm the environment anymore (symbolized by Hina not being tied to the weather at the end of the story). One can only hope it won't get worse, but considering no other city got submerged underwater other than Tokyo, Shinkai is optimistic Humanity can and will find a way to contain the damage we have done.
In other words, just like he portrayed Hodaka and Hina achieving, Shinkai is hopeful Humanity can also find our happy ending despite the environmental damage we already have caused. That is a very powerful message, and is the reason why even though Your Name may be superior in a technical and narrative sense, Tenki no Ko/Weathering with You is still IMO the 'better' movie. (Not at all unlike why I also think Princess Mononoke is Miyazaki's best film, even over Spirited Away, but I'm really digressing at this point.
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