Vampire and Immortality

My name is An Ran, I think I am dead! But I was resurrected and became a vampire... An Ran was originally a college student. In order to eliminate the pressure of study and life, he would go to live with his grandma in the countryside for a period of time every holiday. One day when he went out to herd sheep, he picked up a dark red ring in a mysterious cave. By accident, the blood left in the ring invaded his body. This is the blood left by a vampire, so not surprisingly, An Ran also became a vampire. While gradually accepting his identity as a vampire, he unexpectedly learned the secrets of the world of immortality. As a result, An Ran took on the identity of a vampire and embarked on the road to immortality by accident...