Deutsche Bahn is notorious for being late or having technical problems. It's like a running gag. Everytime I have to take a train in Germany, I make sure to have at least 1-2 hours between connecting trains/flights.

And yes, Japanese trains are crazily accurate. Not only are they (almost) always perfectly on time, they also stop exactly at the position that is indicated on the platform, so you can line up and wait right in front of the train door.