MeruPuri: Märchen☆Prince, Adarshan no Hanayome Recommendations
Especially the age-difference about the main characters and "Kingdom" things. Main guy is older this time, again a prince and other girl is 10 years old princess. Just the opposite of Merupuri you can say.
Both center around the lives of aristocratic couples and their everyday lives. MeruPuri focuses more on magical issues and realms while Adarushan looks at political issues. Both main couples have a considerable age difference.