I have never read the 70's manga by Shinichi Koga, so I cannot say how well the film follows its source.
I first saw this a decade ago on a Japanese grocery store rental tape without subtitles, but this first film had such a straightforward minimal plot that a full translation wasn't really necessary to follow the story. After seeing it subtitled, I feel the same way I felt back then: It's a decent low budget splatter film with witchcraft elements which seems to have spent the bulk of its budget in about 3 minutes of CG SFX scenes at the end of the film. Almost the entire film takes place in the school, but the limited setting doesn't hurt the film.
It's a pretty decent low budget film, but as the director stated is basically more of a relationship film with a horror backdrop than a typical horror film. I liked Kimika Yoshino in the lead role and thought she wasn't bad for a gravure model turned first time actress. Miho Kanno plays her new friend who shows her around school. You may recognize her from her role a few years later as the first Tomie. Prolific actress/voice actress Ryouka Yuzuki (aka Kanori Kadomatsu / Ayumi Nagashii) plays a schoolgirl who is having a lesbian affair with the teacher played by Mio Takaki (an actress from a few Ultraman films). The lesbian affair and its resulting nudity seems to be an idea of the producers to appeal to the exploitation audience and really doesn't add anything to the film.
STORY: Misa Kuroi is a witch who battle the forces of darkness and tries to protect the innocent, not that she has too good a track record for saving her friends, as she readily admits. Unfortunately for her, the trail of deaths left in her path makes some see her as an evil occult murderer, when in fact she just goes where the danger happens to be. She's somewhat of a victim of circumstance in this regard. She transfers in to a new school where five local murders have made a pentagram of blood and now an evil cult plans to kill off 13 more hapless victims to bring Lucifer into the world to obtain his powers. A group of students has to stay after school to retake a test and is trapped inside, trying to escape what seems to be a certain and rather messy death at the hands of an unknown enemy. The resident 'goth' kid has read some books about magic and decides Misa's knowledge makes her the number one suspect.
Sadly, the subtitlers at Tokyo Shock have an issue with consistency as they use at least 2 or 3 noticeably different spellings for the 3rd line of the Eko Eko Azarak chant. Luckily, the DVD is packed with extras.