Germany/England is a pairing between the two characters, Germany and England. It is commonly known as GerEng, depriving from the first 3 syllables of both of their names or GerUK. Potato Tea can be consisdered a pairing name.
Germany and England have quite the history during World War II, with Germany being a part of the Axis Powers and England in the Allies. There aren't many interactions between them. After being beaten by Germany, England wanted to take a revenge on him by summoning a demon but was interrupted by America and Russia's head poked out of the diagram. He then attemped to take revenge on Germany by using the Busby Chair but failed as Russia sat on it instead and destroyed it to pieces. England had given up to take revenge on Germany ever since those attempts.Germany and England are fighting each other during World War II and it is coincidentally Christmas. That day, England thinks about the celebration and walks up to Germany's battlefront, inviting for both sides to play soccer and forget about fighting or being enemies. Germany agrees and they play soccer together and go back to fighting at the end.
This pairing is an uncommon pair meaning that it has a few fans pairing these two.