Interesting story about this film: I remember before I turned ten seeing a Columbia VHS cover featuring a young lamb, but then didn't put a name to it, although it remained well-engraved in my memory, which I would describe as semi-eidetic, being autistic. It wasn't until around my mid-thirties that I glimpsed fanart of a sheep wearing a bell named Chirin, and a little internet research ultimately led me to the Wikipedia page of an old animated Japanese film called Ringing Bell, along with the very VHS cover I remember seeing back in my youth, so I decided to give it a watch.
The film opens with a blizzard eventually heralding the coming of spring, along which so does the lamb Chirin, who lives a peaceful life on a farm in a meadow with his mother, who is able to keep tabs on him thanks to her offspring's eponymous bell. However, tragedy strikes, leaving Chirin alone, and feeling powerless and alone, he decides to become apprentice to the very wolf that caused said heartbreak. He trains to become more powerful than the typical herbivore animal, hunting alongside his lupine father figure, soon reaching a situation similar to where the wolf had invaded the sheep's barn.
Overall, Ringing Bell is one of the great tragedies of Japanimation, espousing the lesson that revenge is rarely worth it, containing excellent haunting music, some vocal, which really enhances its sadness. Originally released in Japan back in 1978, the film would see English release in 1983, and had one of the better localizations of Japanimation of the time, but there's some awkward dialogue with reference to the Wolf King as "wolf" instead of giving him an actual name. There is also a bit of artistic merit with regards to the various animals and unresolved questions such as the absence of Chirin's biological father, but otherwise, it's definitely a must-watch for any Japanophile.