Korean people calculate age in a different method although I don't know if they go to school by their Korean age or not.
So maybe one of them was born on 31st December so he turned 2 years old on 1st January and if the other one was born on 1st January he was just one year old on 1st of January?
Because when a baby is born in Korea he/she is aleady counted as 1 year old and averybody ages one year on every 1st January.
I think it’s a translation error. It specifically states one is a second year and one is a third.
im like 10 pages in and how..... are they twins when one is 19 and the other is 18.....?