In Tokyo, two naive sisters from the countryside move into a tiny 6 tatami mat, one-room apartment. They have never experienced city life before, and now they must share this cramped space with their voluptuous siblings! Living so close together ignites desires that can't be contained. One of them remarks about how her breasts were smaller when she was younger, but now they've grown significantly. As young and horny individuals, it's impossible for them not to act upon these urges while sharing such intimate quarters... Note that recording contents may vary depending on distribution methods.