Yumiko and her son Masahiro had a strong bond, but because it was so strong, their bond escalated in an unexpected direction. Wanting to comfort his mother, whose marriage life had stagnated and she felt lonely, the son approached her with that desire, and the mother accepted, wanting to respond to her son's kindness. However, with just one mistake, Yumiko's body became captivated by her son. And her son had an extraordinary streak. He couldn't stop. The two pressed their bodies together to the limit and became immersed in a forbidden world.