Rumi liked his childhood friend Kazuki's brother Masaru, but when he suddenly got married, he went out with Kazuki instead. A few months later, Rumi hears about Masaru's divorce. Rumi, who thinks it's an opportunity, asks her friend Yuka to seduce Kazuki. After visiting Masaru, who was heartbroken about the divorce, Rumi began to seduce him with her body.