It's a shame that you guys aren't continuing this, but thanks for translating this first chapter! Iit's so cute; I hope that it gets picked up quickly!
@Eclat123 koreans has a unique way of counting their age. The moment they are born, they are 1yo, including the time they spent in the womb.
Also, their age didn't increase on their bday. Instead, they get 1 year added on 1st january every year. So if they are born on 31 dec for example, the will be 2yo the next day. If I am not wrong.
From this, safe to assume that the twins was born before 1st january. So they are 20 in their korean age (18yo international age). 20+5 = 25 :)
@Mintzu@Eclat123 They could also be counting just based on the fact that at birth both times they are considered already 1 year old and the translation subtracted one each time? In essence they are considered 19 and 6 so 25?
@asriana I have looked up spoilers on the Korean Wiki, and unless you have read the whole novel series from cover to cover, as long as the wiki says there are no incestuous elements between the two, I'll take the wiki's word over yours, thanks.