Could it be German and trains? I haven't known a country that is so into trains besides Germany. Actually, engineering in general is pretty high all the German guy's interest.
So yeah. Germans love trains, it's true. Japanese love trains and do so in that overboard way which is at once both cool and kind of scary...
On the other hand, I don't know enough about Japan, are they really obsessed about trains or do they just happen to be really really good at trains and use them a lot? They might be just pragmatic about them (quite the opposite of obsessed) and a high presence in daily life would naturally be reflected in pop culture.