Y-Destiny is the story of 7 best friends:
Sun, Mon, Tue, Puth, Thurs, Masuk and Sat, each of whom has different personalities according to their birthdays and fate leads them to meet their loved ones.
ps : 'Y' is a slang used in Thai for Yaoi. So the title could be translated as all of them are destined to be 'Y'.....?? <(￣︶￣)>