Sayuri, a married woman who runs a knitting class, captivates her son Taro with her gentle smile and soft, delicate hands as she crafts her work. However, one day, Taro discovers that his mother is teaching knitting at a friend's house, and a sense of unease begins to grow within him. That night, he heads to his friend's place and witnesses a secretive, intimate connection between his mother and his friend. Overcome by impulse, consumed with jealousy and desire, Taro disguises himself as his friend and suddenly embraces his mother from behind. In that instant, their relationship changes forever. Amid a warm yet unsettling atmosphere, a new, forbidden bond begins to form between mother and son.