Omohide Poroporoおもひでぽろぽろ

In 1982, Taeko is 27, unmarried, has lived her whole life in Tokyo and now works at a company there. She decides to take another trip to visit her elder sister's in-laws in the rural countryside to help with the safflower harvest and get away from city life. While traveling at night on a train to Yamagata, she begins to recall memories of herself as a fifth-grade schoolgirl in 1966, and her intense desire to go on holiday like her classmates, all of whom have family outside of the big city.
During her stay in Yamagata, she finds herself increasingly nostalgic and wistful for her childhood self, while simultaneously wrestling with adult issues of career and love. The trip dredges up forgotten memories (not all of them good ones) — the first stirrings of childish romance, puberty and growing up, the frustrations of math and boys. In lyrical switches between the present and the past, Taeko wonders if she has been true to the dreams of her childhood self. Finally, Taeko faces her own true self, how she views the world and the people around her, and has to decide what kind of person to become.

From: Wikipedia