**Synopsis:** Kazuya Kinoshita is a fairly ordinary college student who has just been dumped by his girlfriend, who decided to move on. Devastated and feeling at rock bottom, he decides to download the new trending app, Diamond, on his phone and rents a new girlfriend to feel better. He ends up meeting a certain Chizuru Mizuhara, a young woman who, at first glance, seems to have everything he's looking for.

This vinyl includes songs dedicated to each girl from the anime (Ruka, Chizuru, Nami, Sumi) sung by their respective Japanese voice actresses, as well as the corresponding instrumental versions. Each song reflects the adventures, thoughts, and emotions that each of the girls experiences.