Lesbian sisters Azumi and Reiko have been secretly meeting in their daily lives. One day, their relationship is discovered by Ayumi, Azumi's younger sister. Witnessing the scene, Ayumi is overwhelmed with confusion and shock. Reiko, seeking to understand her feelings, gently begins to warmly explain the beauty of lesbian love like an older sister. This tenderness and pure emotion deepen the bond between the two, portraying a more intimate relationship.