In the 4th installment, we will have the mature Reiko Sawamura whisper lewd words to us in a relaxed and indulgent manner. Enjoy the classic big sister-type pervert's lewd words, fun and comical lewd words, condescending queen-style lewd words, and finally, the loving lewd words of a wife. Please enjoy the 'whispering' to the fullest, taking advantage of the characteristics of binaural microphones. This is the 4th installment of a series of works that, through subjective shooting, make the viewer feel as if they are really being whispered to, with word-based eroticism.