Be with You

The woman who reappears with no memory in the rainy season, a year after Mio's death, is revealed through her diary to be Mio's younger self visiting her family's future. The six weeks she spends with Takumi and Yuji, which fill most of the film, are therefore the time travel, and the final act shows her returning to her own time and choosing that short life knowing how it ends. The premise underlies the whole story, but it is concealed as a ghost-style return until the reveal and the film never explores how it works, so it stops short of 8.

The apparent return of a deceased wife is explained by her younger self visiting her family’s future.