This is perhaps one of the movies I've cried on. Literally. I cried BUCKETS when I was watching this movie.
It all starts where Aoi Takumi (Nakamura Shidou) and Aoi Yuji (Takei Akashi) live together in a house where Takumi's wife, Mio (Takeuchi Yuko), was still alive. But due to an illness she died.
After a year of her death, they remember her promise saying that she will return once the rainy season arrives. Thinking that it's impossible for her to come back, they have their hopes up.
Once the rainy season arrives, they go to the place where Yuji and Mio placed their "time capsule". Takumi and Yuji then see Mio sitting by the #5 door. She's back, but has no recollection of her memories with them whatsoever.
Takumi and Yuji then bring Mio back home to their house. Still having no recollection of who they are and what her life in the past was.
(I'd say more, but I'd be spoiling the whole movie!) If you want to know the rest, I'D WATCH THIS MOVIE. FAST!!
http://www.ima-ai.com/ official website (Japanese)
http://www.tbs.co.jp/movie/english/bewithyou/ official site (English)
http://global.yesasia.com/en/PrdDept.aspx/code-j/section-videos/pid-1003968861/ Official DVD
Notes: They also made a dorama for this movie. :D
http://wiki.d-addicts.com/Ima_Ai_ni_Yukimasu