Welcome to the Café of the Dark Guild’s Successor

The “Raven” Dark Guild’s talent training facility.
That’s where my younger brother and I were dragged because of our father’s debts.
Hoping that at least my brother could grow up safely, I managed to get him out, and from that day on, our paths split completely.
He became the beloved son of a noble family, while I became the promising heir of a dark guild.
Ten years passed, and unexpectedly, I was finally given a chance to leave the guild. After much thought, I returned to the small shop where I had spent my childhood with my parents.
I planned to run it quietly as a small business while using it as a branch for the guild, but—
…Why does the shop keep getting more popular?
Because of my brother, who has now become the empire’s most popular man, the shop, tucked away in the middle of a mountain with no proper roads, suddenly has lines of customers.
Can I… stay the night?
A priest from the building next door randomly shows up, asking to sleep over.
“Be my fiancée.”
And now I’m getting entangled with a prince, who also happens to be my brother’s superior.
And on top of that, this shop—no, my late parents—turn out to be connected to the Great Mage War, which I thought ended 600 years ago? …Wasn’t I finally supposed to live a peaceful life?