Noah

He is a prince of this kingdom. However, he goes to a normal school to study society. At school, he uses a false name, Al. The only person who knows that he is a prince is the second prince of a small neighboring country. His real name is Carmen, and the name he uses at the school is Cain. They are 17 years old and Noah will be king with Princess Noelle as his twin when he turns 25. That's all there is to it. You can be Carmen or any other classmates.