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.

According to Kadokawa, an OVA of R-15 will be bundled with the tenth volume of the novel.

R-15 is about a boy, Taketo Akutagawa, who attends a school for geniuses: Inspiration Academy Private High School. Taketo is a genius novelist and writes erotica. Despite negative perceptions many people have of him, he aims to be at the top of his class and be recognized as the world's greatest writer.

Life at the Rainy Color café can never be described as boring. The arrival of the Koga brothers from England—Noel, always brimming with curiosity, and Nicola, somewhat shy and conservative—ensures that their sibling, café manager Shion, is kept on his toes. There's also another newcomer, cameraman/photographer Jun Arisawa, who holds a mysterious connection to café owner Koji Amami. Last but not least, there's a special photograph that incites all kinds of heartfelt and comedic reactions from the Rainy Color crew!