World War II
The two countries, looking upon real history, have had secret relations documented back to the Tokugawa Shogunate. Their relationship was most likely strained after the events of World War II, however that doesn't mean that their relations are continuously strained into modern-day settings, and their relationship does not imply any openly-harbored grudges on either side.
The two countries now have a wonderful political relationship, sharing similar interests in things such as science and technology. There is even a street in Germany named after Hiroshima.
If you would like more info on the real relationship between the two countries, look up German Japanese Relations and you will see that their relationship is a rather strong one.
In real life, Japan even celebrated 150 years of Japanese-German relationships from November 2010 to February 2011.
There aren't many fans of Germany/Japan, although they are both part of the small group of the Axis Powers and share almost all of the same knowledge and intelligence. Many fans have their debates about this couple because Germany/Italy is more popular than most couples out there (including this one). Since there have been more interactions between Germany and Italy, the Germany/Japan relationship doesn't seem reasonable to most fans.
Webcomic: Main Storyline
- Hetalia Chapter 4: Pact Of Steel
Webcomic: Extra Stories
- You Know Wer're Kind Of...
- We're Shipwrecked
- National Foundation Day
- Salted Salmon
Webcomic: Comic Diaries
- Comic Diary 3