I have never read the horror novel upon which Ringu is based, but I've been rather discouraged by what I've read about the book in popular media. I suppose this is often the case with effective movies based on popular fiction, e.g. Stephen King's The Shining or Nasu's Fate/ visual-novel material which gets polished up into anime series and movies. That process can be a total bodge job (q.v. PJ's LOTR) or it can tighten up a verbose and vacuous mass of novel-writing (q.v. JKR's HP) into an effective and emotionally gripping narrative.
Thus, to me, the 1995 film adaptation of Ringu is basically canonical. When I think of Sadako and her tragic life, I'm referring chiefly to that movie, which wisely omits some nasty subplots from the novel in order to give us a painfully sympathetic cast of characters. The horror is always more horrific when it's unexpected, visited upon someone who doesn't seem to "deserve it". U.S. #horror films have been shaped by the demands of right-wing Christians, so American horror films tend to come across like divine punishments for furtive sins. It's not as scary as horror that lights on someone you want to live.
(cont'd)