Xowin said:I just finished the movie today, and I wish I saw it earlier so I could participate in past forums that are 5 or 6 years old. The most logical theory I read is that Chiaki is on a mission to retrieve this painting without letting anyone know that he's from the future. He unfortunetly finds a time where the painting isn't restored, so he tries to find someone to restore it for his future: Makoto.
Just how significant is such a painting!? He tells her that he would go through any danger just to see it and to me that's just a horrible story if he truly went back in time just to "see" a painting and thats it. There has to be more to it than that.
When Mokoto asks if the painting had anything to do with his future, Chiaki changes the subject which makes you even more curious of the painting's significance.
And finally, in Chiaki and Mokoto's final exchange, he tells her "I'll be waiting for you". Re-watching that part after reading the theory brought me chills. Mokoto responded "I'll come running", but she may not be on the same page.
Chiaki may have been talking about the painting, but Mokoto was thinking he meant they would somehow meet again. If you watch the scene, Chiaki pets Mokoto like a dog after his remark. Its like he really is just using her, like he assigned her with the task of restoring that painting. There was no romance involved on his part.
Also before that, when Mokoto started time leaping to avoid Chiaki asking her out, it didnt take long for Chiaki to find another girl "that he could use". If he truly loved Mokoto, he wouldn't have just skipped to the next girl that quickly. Also, when he finds out that he has no more time-leaps left he says something along the lines of nothing matters anymore. With that being said the theory doesnt support the fact that Chiaki used his final leap to save his friend, but maybe he really did cherish his friendships and they got in the way of his mission. After all, while he was dating the other girl that he might have planned to use, he did still go and hang out with Mokoto and Kosuke.
Chiaki's prime ambition was that painting. In what seems like a horrible future, why would you go back in time just to look at a painting. What is so great about the painting?! What do you think? Are there any better theories that I've missed?