The future is post-apocalyptic, but also more mystical and nature-basedThe future described seems to be one where the world is unlivable to a far extent, with the sky unseeable and the population far smaller. This implies a heavily polluted future, with the sky choked with smog. However, they don't just use their time travel to fix this, so there must be some other reason. Perhaps in the future, the dominant religion is extremely hippie-esque, with the idea that they shouldn't interfere, but also that they need to fix the world. Because of that, breeding is restricted (free, unlimited contraception, perhaps), leading to smaller, more manageable populations that don't require massive pollution. Additionally, time travel is seen as somewhat mystical, which is why the battery looks like a nut of sorts. It's designed to look natural.
The opening scene wasn't just a dream; Makoto was either killed or severely injured by the baseball hitting her in the head.This made Chiaki use his last leap in that time line to go back in time to save her, which in turn is why he's there when she stumbles onto the time travel device; running out of leaps made him finally sit down and figure out where he lost it so he can recharge. Later in the movie he's not there when she goes back to figure out who startled her because during her time leaping she's gone to the past before that day before, wiping out the version of him who ran out of leaps so he still had one left and didn't need to go find it. This is a very lucky break for Kousuke and Kaho. Makoto unknowingly ends up paying him back during the course of the movie, when she leaps to save him from having his head bashed in with the fire extinguisher.
Makoto will be the inventor of the time travel deviceEarly in the movie, she's considering whether to study science or not; her aunt says that she's not the type to just wait for a guy, she'll go find him; she tells Chiaki at the end that she'll "come running" to meet him in the future, and finally, at the very end, she tells Kousuke that she's made a decision. The decision? To study science and eventually invent a little walnut that charges you up to travel in time! You could even take it a step further and say that Chiaki's real reason for traveling back in time was to be the impetus for Makoto to invent the device, thus creating a Stable Time Loop. I interpreted it rather differently. Her aunt, or rather "aunt" is person from future sent by Makoto/her coworker/her descendant (I doubt she is future Makoto) to preserve this painting. She promised that she will take care of it, after all. It explain also strange reaction to her story, telling about leaping, encouraging Makoto to leap etc. This was of course to start this whole chain of events that will end in sending "aunt" to future. And decision, by the way, was to be historian and preservator.
Chiaki's Time is Less Than a Decade in the FutureThus having Makoto wait for him be not quite such an incredible task. Baseball only disappeared because the Boston Red Sox won another World Series, which coincidentally caused a low level apocalypse. Time travel was invented as well.
The painting survives to Chiaki's time as a result of him traveling to the past.In the original unaltered timeline, Makoto dies by being run over by the train, and the painting vanishes at some time thereafter. Chiaki's trip to the past results in Makoto avoiding her fatal train accident (as a result of acquiring Chiaki's time travel ability), and her relationship with Chiaki spurs her to succeed her aunt as caretaker of the museum's art. Makoto's work then allows the painting to survive to Chiaki's time.
Aunt Witch is MakotoThe timeline begins. Makoto befriends Chiaki. Their feelings for one another grow. Makoto finds the time travel device. She has fun messing with time for a while, until she realizes she's out of leaps. Tragedy strikes. She has to watch her friends die because she couldn't save that one last leap to keep them alive. Then everything stops. Chiaki approaches her and tells her everything, including that he used his last leap to save Kousuke and his girlfriend. Unfortunately, Now that he's broken tardis protocol, he must dissipate into the void, or go back to the future to face trial for temporal crimes or something, and what's worse, he never got to see his painting. It's okay though, because Makoto has one more leap, right? Wrong. She doesn't have one more leap, and the love of her life is gone forever. She never planned to wait for him. Jump 15 years. Time travel is invented. She finally has the chance to save Chiaki, but she's too old to do so as herself. So she goes back, further than Chiaki. She goes back to around the time of her birth. She befriends her own mother and receives the affectionate nickname "aunt witch". Now she has an in. She can help herself by convincing young Makoto that her frivolous leaping may be hurting someone else, perhaps just enough to give her that one last leap that she need to save Chiaki, (if a boy is late in meeting up with you, you're the type to go look for him). But why? Why did she go back so far? Why did she have to be there so long before she even met Chiaki? Simple: she wanted to give him his painting. She needed time to hone her craft, make a name for herself, and use that name to get a job as the restoration artist in a high class museum so that she could restore the painting that Chiaki traveled so far to see.
Makoto isn't travelling through time, she is hallucinating/her memory/perception of linear time is brokenDid you see just how many times during the movie she bangs her head against hard objects? Something in her brain was bound to get damaged at some point.
The Japanese language evolved greatly by Chikai's eraIIRC, they mention at some point that he cannot read Kanji at all. One explanation could be that in the future he came from, Kanji isn't used anymore. Languages change all the time, and we don't know how far his future is.
Chiaki lied about why he traveled from his time. The painting was probably important, but Future Makoto, whatever age she was, told Chiaki to lie so that through him, she could create a Tricked Out Time loop.
Chiaki is from the future of Gurren Lagann .And he and Makoto are obviously Simon's parents, because Makoto resembles Shinji Ikari Chiaki only female and hyperactive. said he lived in a small population and did not see the sun because of Beast People and their Ganmen mechs.
Makoto's mother is Satsuki, grown up.They look so alike that it has to be considered, and it actually makes quite a lot of sense. My Neighbor Totoro was set in 1958, when Satsuki was around nine or ten years old. Makoto, in her canon anime, is around 17, and let's say we're assuming that The Girl Who Leapt Through Time is set in 2006, when the film was released. That means that Satsuki would have been around 41 when Makoto was born and a little bit older when Makoto's sister was born, which is still an age at which many women would be able to conceive children.
Chiaki is a Time Lord....It was required.
Makoto never leapt through time at all.It's only after the train scene that thing really start to get weird- beforehand during the baseball game, it was confirmed she was just dreaming until her younger sister woke her up. Makoto got hit by the train and is comatose- Chiaki confesses to her while she's comatose, Kousuke, Yuri, Kano and the rest of her family visit her. When she promises Chiaki she will hurry up, he was actually asking her to wake up soon and find him. The red lines that reappear also look, from far away, like a heart monitor.