【A live-action collaboration with the popular work of the popular doujin circle "Kurambon" is realized, welcoming healthy busty beauty Nami Nami as the main character!】The brother who was suddenly confessed to by his stepsister tries to refuse with reason, but he can't resist her extreme and cute charm and finally crosses the forbidden line. From there, the two who can't stop seek each other at home and in love hotels, spending days entwining their bodies many times. Meanwhile, the brother's chest is weighed down by the guilt of "Is this relationship allowed?" while the sister, ignoring the brother's hesitation, approaches him more boldly... What is the "final decision" chosen by the brother who is cornered?
