Although she's of middle age, her heart is still that of a woman… Aki, a new part-time worker at a convenience store, finds herself without a sex life due to her husband's absence as he takes a new post alone. One day, while changing clothes in the office at her workplace, a male college student sees her large buttocks. From that embarrassing scene, the student learns that she "likes married women with large buttocks," and their relationship gradually deepens…