Can you recommend a novel about vampires?

The male protagonist was an elegant and handsome vampire. After he became an adult, he was sent by his father to study in a place similar to a magic school.(In fact, vampires only have one lover in their lives. His father's move was also to let him find someone who could accompany him for the rest of his life.) Due to his noble bloodline, he did not need to suck human blood. Animal blood was also fine. He would go to the sea near the school to suck the blood of an animal, but the blood tasted terrible. Once, when he went there again, he was seen by a woman (the female protagonist). The female protagonist used his identity as a vampire to threaten the male protagonist, wanting him to help her with her experiments (the female protagonist was a genius inventor), but apparently she had the wrong idea. The male lead had determined that she was his when he first saw her. There was also a man who was childhood sweethearts with the female lead. He had red hair, was good at fighting, and was infatuated with the female lead. But the female lead was extremely slow. The red-haired man and the male lead became love rivals. The three of them were all influential figures in the school. The leader of a mercenary group valued this business opportunity and tricked the three of them into joining. The four of them took on difficult cases outside the school, such as taking down a bandit's lair, to earn money and pass the time. Although the four of them had different personalities and beliefs, they had become life-and-death companions. The male protagonist's father had a high position in the family, but he lived in seclusion with his mother and the male protagonist. He was also very famous in the entire continent and was a figure that was looked up to like a god. Back then, he fought a certain demon and became famous as a hero who saved the lives of the continent from fire and water.(However, the actual reason was that many animals died in the chaotic battle back then, leaving only some animals with unpalatable blood. His father was angry that he could not find sweet blood, so he showed his might...) The male protagonist's mother was a human and had passed away (because humans had shorter lifespans than vampires). His father was infatuated with her. The female protagonist had the blood of the demon race and the god race, and she had six brothers who had a strong love complex for their sisters. Her brothers were handsome, and her parents were also beautiful. Although the female protagonist was delicate, she was far inferior to her brothers, making her feel inferior. However, the reason was due to the special bloodline of the demon race. Demon girls would undergo a metamorphosis when they reached adulthood. Uh, from an ugly duckling to a white swan. Oh, and that leader, his background wasn't simple either. Although he appeared to only care about profit, he was the heir of a very powerful family. However, he wasn't willing to live under the control of others. He was very rebellious and black-bellied.