A piece of junk mail for a rental pet shop catches her eye. Thinking that a pet might be just the solution to helping her relax from a hard day at work, Yui places an order with the company. However, it isn't an animal that shows up on her doorstep, but a rascally hound of handsome young man! Right there in the doorway, he informs her no uncertain terms that a "physcial compatibility check" must be conducted! After which, she then performs the same "check" with a handsome serpentine gentleman, in a wet, slick tangle of bodies! And remarkably enough, she end up in a hot, jealous-fueled menge trois. When pressed about which pet she will choose, Yui decides....?