Ookami Kodomo no Ame to Yuki (Movie) Wiki

The theme of the film is the love between parents and children. The story covers 13 years and begins with a 19-year-old college student named Hana who encounters and falls in “fairy tale-like” love with a “wolf man.”

After marrying the wolf man, Hana gives birth and raises two wolf children: an older sister named Yuki, born on a snowy day, and a younger brother named Ame, born on a rainy day. The four quietly live in a corner of a city to conceal the existence of the “wolf children,” but when the wolf man suddenly dies, Hana decides to move to a rural town far removed from the city.

Source: Anime News Network