Kaze no Matasaburou  

Matasaburo the Wind Boy, Matasaburo, le garçon du vent, Miyazawa Kenji Meisaku Anime Series: Kaze no Matasaburou, 宮沢賢治 名作アニメシリーズ 風の又三郎, 風の又三郎

A new student from a foreign country comes to a small town in Japan. His mysterious demeanor earns him the nickname "Matasaburou the Wind Imp" among his classmates, who are fascinated by him. Despite being from different backgrounds, they become friends and spend many days exploring the countryside together. On a windy day, Matasaburou returns to the city, leaving his friends wondering if he was truly Matasaburou the Wind Imp and whether he flew away on the wind.