Back when I had the patience to read a raw, never mind Inumarudashi, I tried translating chapter 5 part 1. 6 pages long, but riddled with so many obscure cultural references: about one every page. I still can't believe I got through the whole thing, but I'm pretty sure I got about at least 90% of the references.
Dealing with wordplay is also a challenge that can never be perfectly rectified between languages. It's like a non-English speaker trying to watch a kids cartoon made in Canmerica dubbed into their own language.
To give you an idea of how obscure a reference can be, picture this:
Let's say a VA once voiced a certain notable line for an anime from the 80s, about 30 years ago. Now, there are many ways to translate a sentence from Japanese to English, mainly because Japanese sentence structures tend not to have as much variety as in English, so translators can play around with the order of the words to see what personally fits best from a literary perspective. So you can't expect them all to translate the same Japanese line the same way to English. You also can't expect them to catch every last reference, especially if it's from such a long time ago.
So unless your native language is Japanese and you understand their pop culture as fluently and as deep into the past as a native, to the point where you don't depend on fansubs to watch an anime, you would
never notice the VA referencing this exact same line again for an anime from the current decade.
That's exactly what happened when late VA
Kenji Utsumi made a cameo for Beelzebub, specifically to voice a line for
a very minor character powering up that he once voiced as
Raoh from Fist of the North Star as his dying words.
You can see for yourself by comparing these three videos of Utsumi voicing the exact same line, but getting translated differently:
1.
http://www.youtube.com/watch?v=S5eTfZ0hc4Y&t=3m58s (Fist of the North Star, video game)
2.
http://www.youtube.com/watch?v=n3vEktVRvUY&t=5m33s (Fist of the North Star, anime)
3.
http://www.youtube.com/watch?v=-ad9kP1Jfj8&t=7m43s (Beelzebub)
Try figuring that out without some stumbling and research.
