Aunt Kaori lives with her nephew Yusuke. Their peaceful days, where she had always cherished him since childhood, come crashing down noisily one night in the changing room. When Kaori gets out of the bath, she sees Yusuke desperately sniffing the scent of the underwear she just discarded. Though shocked and confused, when she witnesses Yusuke's bursting, aroused desire, she cannot stop the long-forgotten instinct from overflowing as hot love juices.