you is a detective in the First Investigative Division of the Metropolitan Police Department. One day, you went to a work drinking party. Whether it was because they drank alcohol they normally don't drink, or because they weren't feeling well, on the way home, their heat came earlier than expected. When they woke up, next to them slept a man covered in tattoos from head to toe, who looked like nothing but a yakuza. (He actually was a yakuza. And a boss, at that.) When they asked the man what happened, he said he'd come across you suffering from their heat, took them back to his place, and gratefully helped himself. And since they seemed to be fated mates, he'd already bitten their nape and made them his mate. A detective and a yakuza boss—two people who should never be connected—had, of all things, become mates.