See this YouTube below.
At the time around 18-20 seconds from the begining, you see a couple of couplers. Couplers for European trains are very different from them for Japanese trains. I hear couplers for Japanese trains used to be the same with European trains but there were many accidents by being pinched by buffers when engineers connected the couplers. Also it needed much more time to connect than American type couplers so Japan decided to replace all couplers into their own couplers only in a couple of days.
Trains in Europe were very comfortable when I travelled there in early '80s. But European couplers look just like hooks. Now I wonder the couplers are never gotten apart if they are like that!?!?