@Braverave
In Japan, the school year starts in April and ends in March. Children who were born between April 2nd and April 1st of the following year [ie April 2, 2020 to April 1, 2021] are placed within the same grade. This could change your child's grade when you move to Japan from another...
Personally, the only person close to the Princess I tolerate and wouldn't mind live after the shitstorm is the Mama's boy fiancée. Unless the author gives us a backstory of him being a grade A dick, He's just too much of a loser to be a threat.