there are many things that dont carry over well, just because the vast difference in our cultures. Then there is even more due to the slang that carries over. Some words just dont have a equivalent in another language.
For example there could be a word that is used to describe the love you have for a friend/family, and another for someone you are romantically interested in, and a other for the physical "love" you have with a partner.
In english there is just love. It is a blanket term.
If there were a proper translation, then the translation would lose its effect.
For example. The japanese word "nakama", means friend. However it is more of a friend you have a deeper bond with, and are very attached to. That person is like family.
So if it is translated in english, you just get the word friend. However in english friend is usually someone you just enjoy to hang out with. You may or may not consider that person to be like family. You may not even like a person that much, but may still be friends with them.
So the sentence " you are my nakama" translated to english, a correct translation would be " you are my friend whom i consider to be family, and like a brother to me"
So multiply this by hundreds of words or more, and you would get some really detailed sentences haveing to specify the word.
A other example, is names of objects/people. Minato namikaze means roughly "harbor Wave" However because Minato is his name, it is not translated.
Rasengan means swirly ball. But that is something else that is not translated.
But mostly the translations are pretty great, and get the job done nearly the best it can. But some of it is just lost through translation. But you dont have to be a native speaker of japanese to fully understand the japanese that is said and its references. You do have to have a great knowledge of it though.