Once upon a time, Sanrio--best known as being the makers of Hello Kitty and friends--was in the habit of making animated features, and they were pretty darn good stuff. If you're an aging and decrepit fossil of anime fandom (that is to say, older than your mid-20s), then perhaps you remember the Unico movies or Sea Prince and the Fire Child. These movies, having never been re-released on DVD, were largely forgotten for several years, until one daring and intrepid man equipped with a VCR and a PC capture card decided to do the "fansub tape God" equivalent of Prometheus bringing fire down from Mount Olympus to give to us mere mortals: he made digital captures of his VHS tapes and made them available for download.
So it is that finding information online regarding Ringing Bell can be kind of tricky. Running only about 45 minutes long or so, it isn't something people would normally classify as a "movie," but hey, it was the 70s and OAVs hadn't quite existed yet. It's about a cute little lamb named Chirin who loves to frolic and play, and everything seems like the Sanrio we know and love...until the big bad wolf shows up and slaughters his mother. Fed up with his lot in life, Chirin vows to become a wolf himself rather than wait to be killed and be completely powerless to stop it. It's almost a shonen-style "never give up on your dream!" tale, except for the part where you have to abandon your soul and walk the path of Hell. Ogami Itto would be proud.
If you want to learn more about this obscure bit of Sanrio lore, I reviewed it in greater detail on Show # 43 of the Anime World Order podcast. There's also a link to download it via BitTorrent!