The plot focuses on the extreme difference between their refined daytime personas and their submissive, masochistic roles at night.

While specific "Extra Quality" technical lists are often vendor-specific, these versions generally include:

If you’ve tried standard vegetable or drugstore soaps and found them drying or short-lived, this is your upgrade. The Extra Quality line focuses on:

Information regarding the series is documented on platforms like MyAnimeList The Movie Database (TMDB) manga artist behind the original work? Mazome Soap de Aimashou! - MyAnimeList.net