My first japanese movie is "Love Letter" by Shunji Iwai. Until now I still watch them when I have time.
I think this movie is really simple yet beautiful and also rewatchable. In the current trend of crime, medical, or complicated movie and finding love, this show shined because of its simplicity and sincerity. They have added values that every movies dont have. They are not finding love but someone who she was really curious privately. It was just beautiful plot, casts, story and even cinematography. You can't help but fall in love with it.