In a mountain village where rice farming is the livelihood, live mother Kyoko Yabuki and her son Shigeru. This year, poor weather has led to a bad harvest. When the village chief tells them of "Nigigi-sama," a deity of bountiful harvest, Shigeru learns of a traditional ritual involving offering a woman bound with rope to the god. He begins to devise a plan to bind his own mother and offer her as a sacrifice. Kyoko, a beautiful mature woman, feels shock and confusion at first, yet gradually comes to understand her son's intentions. The story unfolds with intense emotions, exploring the deep bond between mother and son, as the ritual brings unexpected arousal and revelation. A tale where tight bondage, deep masochism, and raw familial desire intertwine.