At the Beginning, the Eldest Lady of the Vampire Clan Was Saved and a Contract Was Concluded!

Gu Yuecheng traveled to a parallel urban world where spiritual energy was initially revived, and became a demon slayer hidden in the mortal world by the Demon Slayer Division. At the high school dance, he accidentally rescued a girl who was being chased by a half-demon. However, she didn't expect that the girl was the eldest lady of the vampire clan, one of the thirteen clans of the vampire clan, and accidentally formed a blood contract with Gu Yuecheng. Since then, there has been a "blood-crazy hunter" in the world who can't wake up during the day and preys on monsters at night. ........ How come I became the True Ancestor of the Blood Clan when I met a demon slayer? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.