Due to my wife's hospitalization, my mother-in-law came from her hometown in Sapporo to help with household chores. She's 51 this year, but she's so slender and has such overflowing large breasts that you wouldn't believe it! Living alone with my mother-in-law, my husband can't help but be captivated by her charm. The distance between the two of them gradually narrows... A secret physical relationship begins, unknown to my wife.