As handy as online Japanese-to-English dictionaries are for looking up individual vocabulary words, automated translation programs tend to spit out much spottier results. A big part of the problem is how much more Japanese relies on context for meaning, which in turn means speakers can, and often do, abbreviate and omit whole words and phrases which human listeners can easily understand implicitly.
Automated programs, though, lack this ability, which means their translations are often missing vital elements needed for the sentence to make sense in English. It’s a problem software engineers and linguists are trying to address, but adding such soft logic to machines is a difficult endeavor.
In at least one case, though, the Google Translate team seems to have been too effective, as trying to convert a Japanese phrase meaning, “Goodbye, my beloved” into English produces a result that seems to have roughly 38 hours of backstory behind it.