Eduard, Camus, Ludwig, Naoji and Orpherus have returned to Rosenstolz Academy after a brief holiday, but things are different in the familiar setting. A new principal is at the helm, and he has plans to change the school in ways that may not suit each student’s tastes. At the same time, Europe is preparing for war, and the proud students are trying their best to become Strahl to serve their country. Honor and righteousness are at stake; who will win this elaborate game of chess?
As Ito Keita looks at the envelope in his hand, he is both excited and worried. Inside is the renowned "Platinum Letter", an invitation to the most esteemed boys-only high school in the country: Bell Liberty. Only the very best students are considered for this special academy, and each must display an outstanding skill or talent to be admitted. So with average grades and no special skills to speak of, why is Keita now finding himself on the bus to Bell Liberty? Will he be able to find his place among the elite, or find out why the school chairman himself issued the invitation?
In a time filled with wars, environmental concerns and issues, there lives a gaggle of beautiful boys that are the personification of the world's countries. Japan, England, France, Finland, Germany and the rest of the boys attend the World Conference and tackle issues like global warming with a heavy dose of fun. Through multiple world wars the gang will traverse deserts, build mecha U-boats and solve the world's problems together!
Yuuta has just left his beloved sister behind to attend St Alfonso Academy: a secretive facility located on a small island in the Atlantic Ocean. There, cut off from the outside world, Yuuta cohabitates with five lovely "Marginal Princes": student representative Joshua Grant, movie star Alfred "Red" Visconti, otaku Sylvain Clark, bespectacled Haruya Kobayashi, and Henri-Hughes de Saint Germaine. Through classes, investigations, and musical numbers galore, Yuuta will experience the life of a student alongside his handsome friends.