The storyline is about a girl who gets reincarnated into the body of a married woman who is married to a duke who is known for being cold and heartless and pays no attention to any women including his pathic wife. But all of that changes because the person who got reincarnated into the new body of the wife of the duke is a civilized woman who has seen it all and knows things from the modern society and because of that. The duke's heart changes and the so-called shitty crown prince also start to catch feelings for the wife of the duke. And so far into the manga, she is the most popular lady in society that everybody looks up to.
The Duchess' 50 Tea Recipes