Taki did not change the future. He created a new universe.
When Taki drinks the sake and returns to Mitsuha's body for the final time, he didn't actually change what had already happened. He instead created and entered a split timeline where the inhabitants of Mitsuha's hometown had survived the falling comet. Back in his original reality, he disappeared.- I don't think that's entirely necessary - Mitsuha's entries (and Taki's responses) being corrupted and deleted from his phone as time caught up to the anomaly shows that time is reasonably mutable in this world, implying that this really could be a situation where actually changing things in your own timeline's past is possible.
Tessie, Sayaka, and Mitsuha's love triangle.
The character's feelings were hinted throughout the film. Sayaka teases Tessie about wanting to see Mitsuha in a yukata. he feels uncomfortable being in close proximity to her, mentioning she is of marriageable age, and went along with her plan to evacuate the town without question. Sayaka seems to be interested in his plans for the future, and the two are rarely seen apart. Mitsuha, however, is a shipper on deck for the both of them. It's possible that after the meteor strike, Tessie confessed his feelings for Mitsuha, but she was too fixated on Taki to notice much else, causing Tessie and Sayaka to end up together instead.The town of Itomori is cursed to be destroyed again and again by comets, but there'll always be someone with body-swapping ability to save its residents.
- The town of Itomori is formed around a large lake, which Tessie implies that it was originally a meteorite crater. Near the town, the mountain shrine is located in the center of a crater-like landscape, and the town itself is the site of yet another meteor impact from Comet Tiamat in the present. Mitsuha's grandmother mentions that hundreds of years ago, there was a Great Fire of Mayugoro that happened in the town once before, and that old documents detailing the incident were all destroyed by the fire, so no one is sure about what really happened. It's possible that the 'Great Fire' is created by someone who received warnings about their impending meteor impact through their body-swapping experience to drive people away, just similar to how Taki!Mitsuha convinces Tessie to blow up the power station to drive the town residents away before the meteorite strikes.
- Consider that it appears very likely that the comet has struck the area at least THREE times. Near the end when Taki is looking down on the twin crater-lakes, he is looking down from the rim of ANOTHER CRATER where the Shrine God's Body is said to be. The three craters are perfectly lined up in a row.
The town is destroyed because of kuchikamisake.
Just who would serve their god human saliva anyway?- Well kuchikamisake is not only real and is used in real life for religious services too. And the Aztec used to offer human sacrifices too. So not the idea of sacrificing humans to the gods is not that far off.
- Mitsuha's mother once body
None of the film actually happens.
The ending montage explores the feeling of missing someone you've never met and being strangely attracted to a place or time you never lived in, which is not entirely unheard of in the real world. It isn't necessarily attached to the kind of events that happen in the film, meaning it may have been just that—a feeling. The body swapping and asynchronous timelines were just fate-driven fantasies meant to drive the characters into finding each other. It would also explain why they never notice the change in the dates when they swap bodies—it was quite literally All Just a Dream.- I like this idea. However, does the disaster really happened or it was all just a dream, too?
The entire film takes place over the course of about an hour.
The film begins in the present day, following both Taki and Mitsuha right up until just before they see each other on separate trains. It's shown several times in the movie that, even if both of them lose the memory of the other, it rather quickly comes back once another flip happens or they are (briefly) reunited. What follows isn't exactly an extended flashback, but Taki and Mitsuha both regaining their memories of the events of the comet impact. Thus, by the time they finally meet on the stairs, both already remember everything. With no way of knowing if the OTHER person knows, though, they pass each other waiting for the other to make the first move. Until Taki finally does... Cue waterworks.Taki and Mitsuha are espers
- And the body swapping taking place is due to Mitsuha accessing the morphogenetic field to SHIFT her consciousness into another timeline, especially in response to extreme danger—i.e., the comet's impact.
The comet is a malfunctioning alien spacecraft caught in a time loop
The comet passes by earth every 1200 years and every single time a piece of it breaks off and crashes into the same place on Earth. What if the comet itself is actually some sort of alien spacecraft that uses advanced technology to fold space-time to travel between the stars. During a visit to Earth, some terrible accident occurs, breaking part of the spacecraft apart and causing the aliens' advanced space-time folding drive to malfunction stranding the aliens in a time loop that recurs every 1200 years. From the aliens' perspective, the accident only happens once, but to the people on the earth, they see the malfunction every 1200 years as the time loop repeats. The body swapping ability that Mitsuha and her ancestors posses to travel through space-time arises from residual effects of being the first to come into contact with the piece of the alien spacecraft that crashed. Like the engines the aliens use to travel through space-time, Mitsuha and her ancestors can travel through space-time via body swapping. They and/or the aliens realized that these abilities could be used to try to break the time loop and right the wrongs caused by the initial accident that broke apart the spacecraft.Futaba was not Hitoha's first daughter, merely the first to survive to adulthood.
From the book of the dead we can see that Hitoha was 82 in 2013, which means she had to be born in 1930 or 1931 depending on her exact birthday. From Earthbound, we know that Futaba was not even 25 when she married Toshiki and died 6 years prior to the film when Mitsuha was 11. How long they waited to have Mitsuha is unknown, but it suggests her age at death was somewhere in her late 30s. Putting these two premises together, we can conclude that Hitoha had Futaba somewhere in her own late 30s to 40s, something that was just not done by people of her era. It seems to make more sense that Futaba was not in fact Hitoha's firstborn, but that she had older sisters who never made it for some reason and thus did not warrant mention. If Hitoha was already no stranger to loss prior to Futaba's death, it would also explain Toshiki's observation in Earthbound that she bounced back very quickly after Futaba's death, because she's already grown numb to it.