A series of works involving country connection multiple crossovers. At least three characters feature in each, and between them, they represent a country's army (represented by Girls und Panzer), navy (represented by Kantai Collection) and air force (represented by Strike Witches' World Witches Series). The United States, the United Kingdom, Italy, the Soviet Union and France each feature in an installment.

Each installment's translated title also is the name of a national or ruling party song (can be a national anthem, but not necessarily).