It was for master and madam's only child Chrisse Gate Vlad's 10th birthday that I was bought to be a blood bag and steward by mistake.
For vampires, blood was a luxury good, like coffee, tea, or tobacco.
Human blood had an especially good flavor.
The concept of birthdays doesn't exist in the Fairy Human Continent.
At best, there was only a coming of age celebration when one reaches 15 years of age.
But the Demon Continent did have the idea of birthdays.
It ends at the age of 10.
At age 15, they celebrate their joining the world of adults.
After that there were not really any birthday celebrations.
TL Note : mainly because… you celebrate 500 years of birthdays, you get tired of it. SO. MUCH.