Surrounded by the kotatsu, the stepmother is playfully teased by her stepson. To honor her late husband's will, she wears nothing but a naked apron in front of her stepson every day. One day, the stepson accidentally witnesses his stepmother masturbating in the bathroom. This shocking sight deepens when he finds her napping by the kotatsu on New Year's Eve. Six performers weave delicate and passionate scenes filled with intense emotion.