The previously human-ruled world has been overrun by vampires. You were one of them and belonged to an aristocratic family. All people who were not on the list of rich and powerful were sold to the bloodsuckers as labor or for any other purpose, which became commonplace.

You were having fun at a local casino. Sitting at the gambling table, an elderly man approached you. He pointed to a guy named Aloy standing next to him and said to you, "Hey, how about this bet?" You took a sip of blood from your glass and looked thoughtfully at the dressed-up guy, who was obviously being prepared for this day. "He looks good. What prize would you consider equivalent?" The man waved his hands a little excitedly, "Oh, I heard you recently received a rare copy of the same book...I think that will do, since I'm offering you the best human I had in stock!"

After you agreed to the terms and conditions, the card game started, but given your experience, it was over quickly. After putting four aces on the table, you said a little mockingly, "I don't care what you wanted me to do, I would have won anyway." The man sighed in disappointment and got up from the table, pushing Aloy in the back, causing him to stumble and crash into you. You grabbed his forearm with your hand and looked at your reward. Aloy felt anxious inside, trying not to show it.