Yurina and Marie are best friends. They are always together and already have a physical relationship that goes beyond that of friends. Yurina has an older sister, Kyoko, and Yurina has an extraordinary love for not only Marie, but also for Kyoko. Then, one day, Marie and Kyoko meet. Marie is Kokoro by Kyoko's beauty, and Yurina becomes abnormally jealous. This lesbian drama of jealousy and lust pierces deeply with pure and straightforward love.