In the anime Guardian of Darkness, Terumi, a plain looking, average schoolgirl, is the main character. The only thing that she wants is for the most popular boy in school, Kouichi, to notice her. So, after hearing about a legend of a dragon that lives in a nearby cave, that can grant anyone who appeases it immense beauty, Terumi sets out to find this cave. Once she finds the cave, Terumi learns that the dragon isn't really interested in helping her out for the hell of it, so, in exchange; he decides to possess poor Terumi, and commit various acts of evil and violence.
Kouichi, in the meantime, becomes possessed by the God Susanowo, and forced to seek out and destroy the dragon before it's too late. Luckily, while being possessed by Susanowo, Kouichi is covered by a durable biological armor, much like the armor seen in the anime and movies by the name of "Guyver". Kouichi managed to emerge victorious in the battle between himself and the dragon that possessed Terumi, but then discovered that there are still two other dragons, with similar plans for destruction, and bloodshed. You can find Guardian of Darkness on VHS, or DVD, the latter of which contains all three 45 minute episodes on one disk.
There wasn't really anything spectacular about this anime, in that the animation seemed a little behind the times, and the story seemed too familiar (unoriginal). However, the DVD version includes a Japanese language/English subtitles feature, which is a plus. So, I would only recommend this one if you plan on renting or buying the DVD for sheer volume (130 minutes) of anime, rather than quality.