Duchess's Lo-Fi Coffeehouse

Roana/Loanna was raised in neglect and isolation as an illegitimate child of the Count Louis family.

She gets married off to Duke Bruggen, who orders her to keep quiet and out of the way. Free from all expectations or responsibilities, she decided to enjoy a leisurely life. She roams around the castle and on a walk, she found a familiar looking fruit in the garden.

Using the knowledge from her previous life, and as a passionate barista in her past life, Roana/Loanna remembers exactly how to brew a perfect cup of Joe, she reproduced coffee to have a something to drink between her readings...

The trouble is, no one in this realm seems to know what "coffee" is, nor its wonderful benefits. As a matter of fact, coffee fruits are regarded as "evil":

"My brain is clearer than usual, full of energy, and new ideas keep coming to me."
"What is this? Is it a drug? What's the name of this drink?"
"...Thank you for letting me experience this."
"I've never had this kind of bevarage before!"
"It's very... very delicious."
"...."

But people from this the world loved coffee too much, and her husband who was supposed to be cold-hearted, act strangely now...

Can Roana enjoy her coffee life properly?