Dark Moon: The Blood Altar

From Wattpad:
Riverfield, a beautiful town by the ocean, is home to the prestigious Decelis Academy. It's also home to seven boys with a secret: they may simply seem like players of the famous sport, Nightball, but they're actually vampires.
To escape from their dark past, they try to lead normal lives as students, other than the occasional hitch since their rival Nightball team happens to be made up of werewolves. But in the end, these seven friends always find strength in each other. Until one day, a new transfer student with curious strength causes the boys' forgotten past to slowly unravel.

Original Novel:
Naver Novel, Naver Series

Official Translations:
English, S.Chinese, T.Chinese, Indonesian, Japanese, Spanish, Thai