Rare

Rare is an unknown nation that woke up in the ocean with no memories of her past. As she gets familiar with her new surroundings, she notices the difference in how people are treated depending on their sex. Because of that, she decides to dress as a man to make it easier to find out who she is and get her memories back. China describes Rare to look "Asian" and because of that, she is more comfortable hanging out with him and Japan.