After the Korean and Chinese versions on this topic from @soyamilkbeancurdpudd and @choitrio , I thought we should have a Japanese one as well! 
Please share what kind of translation issues you come across while subbing from Japanese. Jokes which are hard to translate? Words/expressions with hidden meanings? Anything else that needed your long hard thinking? 
I have worked in Japanese dramas, documentaries and movies doing the English to Spanish translation, and with all honesty the English translation has been almost perfect. That was until they assigned a Portuguese CM in a Japanese drama, and she did a terrible job there. I even left the drama bc I couldn’t deal with that terrible translation and even reported her.