Yosuke's trip with friends overseas was suddenly canceled due to bad weather at the destination, and he returned home late. Feeling depressed, he opened the front door and heard a conversation between a man and a woman from the house, where only his mother should be. "Ma'am..." "Your dick was big and nice... I wonder if I should ask you to deliver a big dick to me again." What Yosuke saw was his mother flirting with a young delivery man. Shocked by the lewd appearance of his mother, who he had never seen or heard before, he was unable to speak, and Yosuke just stood there and witnessed the whole thing...