Puerto Rico is a fanmade character for Hetalia Axis Powers, appearing in fanfiction for the series.
The first known fanfiction with Puerto Rico in it was posted on Fanfiction.net which can be viewed here.
The story revolved around Puerto Rican history and her relationships with other countries, such as Spain, France, America, England and in other fanfictions featuring the character, Mexico. A character by the same author.
Puerto Rico is described as a spicy hispanic woman who likes cooking and taking care of children. She is almost always seen taking care of younger children or cooking. Her favorite food appears to be chicken and rice (or in Spanish, arroz con pollo). Overall, her personality seems to be rather carefree as well as nuturing and somewhat confused.
Puerto Rico in her character design appears to be a tan girl with long black hair. She wears a red rose in her hair (given to her by France), a red scarf, a white shirt (like the ones worn in Puerto Rico during the 1920s) and a blue skirt.
Puerto Rico and America seem to have a good relationship. As seen in the story, American soilders go to Puerto Rico, taking over and changing the island's name to "Porto Rico". America calls her Porto as a nickname. However, the two seem to have an on/off relationship. When America first starts taking over the island, he gives her schools, a health care system and expands the roads. He also takes away cock fighting and the local lottery. The things he does makes Puerto Rico call him a puta (however, because he knows little Spanish at the time, he doesn't notice). America and Puerto Rico eventually warm up to eachother and seem to have a "friendly" relationship in other fanfictions where both characters are present. America also states in one part of the story that since he and "Porto" have been together for a while, he wouldn't mind marrying her. However, Puerto Rico seems to be interested in America as well.
In her debut story, Puerto Rico is stated to have a like/hate relationship with Mexico, but so far, their relationship appears to be a friendly one. They both have similar interests such as music and food, both tend to hang out with America. They also like watching Novellas (Spanish soap operas).
Spain first came to Puerto Rico, giving her her name and raising her. When countries like France and England wanted to take over the island, Spain fortified her captial and defended her using his military. Her relationship with Spain seems to be somewhat of a father/daughter or brother/sister relationship, however this is never confirmed.
France wanted to take over Puerto Rico at one point, setting fire to Spain's colonies and planning to burn the capital, however his attempts failed because of Spain's heavy fortification. France late teams up with Spain in order to defend Puerto Rico from England, who attacks her in 1797. France also gives her the red rose she wears in her hair as seen in her character design.
England docks his boats in Puerto Rico on his way to America, where the two have a brief exchange. However England decides he wants to take over the island, only to be defeated by Spain and France.