Draft for a story about the Phillipines in Hetalia.
First have her show up as a young (about 6 or 7) savage Wild Child Action Girl who Spain "discovers" during his explorations. Spain assumes she's a boy and keeps calling her "Phil". Spain announces he's "taking him home with me." Phil fights Spain. Spain sits on her, and has a monologue about how much fun Phil is going to have living with him.
Then America has a fight with Spain. America wins quickly and is a little confused about what he wanted out of the fight. He knows he wants Cuba's freedom (yes, yes, under his supervision, but don't forget that the US Congress made it explicitly clear that they would not annex Cuba, when they certainly had the opportunity), Spain asks, "Is that all?" And then America becoming flustered (not wanting to be thought an idiot) says: "and you have to give me Phil too."
Thus American ends up with Phil (still believed to be a boy, about age 11) without really understanding how he got in this situation. Phil demands her independence. America arrogantly declares that Phil is not ready for independence yet (too young), and insists that America will train Phil right. America and Phil fight. After a rough battle America wins (maybe with a comment about how Phil is tougher than he looks). Have America start wearing a leather neckband to protect him from Phil. Reference the term "leatherneck" for Marines.
Phil now enters training (in the Navy- so we can put her in a sailor suit). America discovers Phil cooks much better than he does. So Phil starts training as a cook/butler/servant.
America discovers Phil is really a woman (now around 15). America is excited because he always wanted a little sister. America becomes less strict and starts displaying a Big Brother Instinct. Phil is now called Phillipine. Except for America who calls her "Philly-chan". (Possibly some scenes with Phillipine cooking dinuguan and balut for America? As a sign that she's not fighting with him as much, but still enjoys making him uncomfortable?)
Japan catches America by surprise while America is busy sitting on the toilet. Japan captures Phillipine. America is injured and hiding in the jungle. Japan makes an appeal to Phillipine for pan-Asian unity. Then he forces Phillipine into a Meido outfit, and declares she shall be his servant/sidekick. (Perhaps with a comment that this will make them more like the European powers, with Philly playing Italy to his Germany).
Phillipine decides America was a much better older brother than Japan. She brings America food, treats his injuries, and together they team up to beat Japan and chase him away. (By the way, Phillipine is still wearing her maid outfit- making her a Ninja Maid for this episode).
America declares Phillipine is all grown up now and ready for independence. He's so proud of her, and proud of himself for doing such a good job raising her. Phillipine gains her independence, but discovers America still hanging out in her house. He explains he never said he wasn't going to visit. "Besides," America says, "I promised to protect you". (Philipine has some arguments with America over the way he keeps dragging mud into her house?)
In the present time Phillipine is still wearing the Maid outfit (running a maid cafe?).
First idea: Is occasionally insulted/hit on by her otaku customers? When this happens she turns away to the camera showing a glare and twitching eye before turning back to the customer and offering a brilliant fake smile. Hinting that Ninja Maid is still in there.
As alternate to the above: Hong Kong and China (and other Asian countries) are visiting Phillipine's maid café. Phillipine has a nice waitress smile for them. Japan enters, Phillipine is rather cold towards him- shows repressed hostility while serving him. (Tsundere?) Displays she still has her ninja skills (using serving platters as throwing stars?) America then comes to visit and when he walks in Phillipine appears to attack him, but America just swats her attacks aside and pulls Philly-chan into a headlock and gives her a noogie- he sees it all as friendly roughhousing. America then sees the other (male) Asian countries and loudly demands that they treat his little sister right and not try to take advantage of her. This dreadfully embarrasses Phillipine. Then America sees Japan, and greets him warmly before telling Japan that he's counting on him to watch out for Philly-chan while he's not there. Cue the outrage from Phillipine. America then waltzes out, oblivious to how he's ruffled everyone's feathers.
Possibly have Taiwan there as well? Perhaps add a conversation between Taiwan and Phillipine about the events?