Miki was worried about her son's social life, as he rarely went out with friends and instead seemed to linger close to her late into the night, touching her body. Growing anxious over his behavior, Miki decided to open up and invited him on a hot spring trip to talk honestly. However, the reason her son had no girlfriend was because he had fallen deeply in love with his own mother. Unable to restrain his feelings any longer, he gave in completely. Bound by the promise that it would be "just for today," the two fell into a forbidden, sweet entanglement, surrendering to each other's bodies.