Yami no Purple Eye
Purple Eyes in the Dark
闇のパープル・アイ
Based on a shoujo manga written and illustrated by Shinohara Chie serialised in Shoujo Comic.
The original story follows the struggles of a teenage girl after she finds herself turning into a lycanthropy-leopard and having to battle her newly found predatory instincts.
In 1987 an animated music video of 30 minutes length was made based on the award winning manga.
(Source: AniDB)