Reiya and Yui became step-siblings after their parents remarried. They had a good relationship without any arguments, but Reiya's affection was a little distorted, as he would sneak into Yui's bedroom and rape her at night, and steal her... One day, Yui went out on a date with her boyfriend and came home drunk. Yui mistook Reiya, who was devotedly taking care of her, for her boyfriend, and started to touch her relentlessly, and even gave her a blowjob. Reiya couldn't resist this, and the two of them finally crossed the line and had creampie sex.