Formulaic Deduction: My Fiancée Is A Gothloli

After completing four years of military service, Matthew Julius returned to his home on the Britannia Islands. He thought he could finally start a new life, only to be informed that he was already engaged. His fiancée was Carrot Olivia, a rising star in the detective world. A mysterious address on a slip of paper and a ten-year-old unsolved family mu*der case are unravelled by the hands of a retired soldier, revealing a vast conspiracy that spans the globe.