No, Japanese phonology and therefore pronunciation (what the grand parent post is complaining about) is one of the easiest out there. There are very few consonants, only 5 vowels, not tone and accent is irrelevant. I don't understand how pronunciation could be remotely a problem with Japanese.
There are also some other easy things like grammar (very few rules, that are quite consistent and composable) and some basic sentence pattern (heck you can make full sentences, sometimes conversations, with a single word [the predicative adjectives]).
> There are very few consonants, only 5 vowels, not tone and accent is irrelevant.
Except that l/r is pronounced differently than most English speakers, the vowels aren't always pronounced yet take up time ("Nan desu ka" is almost always pronounced like "Nan dess ka", for example), and syllable accent is tone rather than volume for emphasis.
You say that sarcastically, but those are all easy things you can master in a week, and they are the sort of thing you might find in the English language or even a dialect. It doesn't compare to learning Chinese or Arabic it seems to me.
Just the fact that you can write out romanji and get reasonably understandable Japanese makes it easier than a significant amount of languages out there.
In my opinion the only thing that makes Japanese truly hard is that they decided for some insane reason to borrow the Chinese writing system, which is the most insane writing system in the world, for half (why half!?) of their writing.
A guess as a beginning Japanese learner: Japanese has a lot of homophones because it has so few syllables. It is also almost always written without spaces. Kanji is actually pretty helpful in reading because it provides semantic meaning that disambiguates homophones as well being more terse and breaking up the writing along grammatical boundaries.
I'm approaching this from the angle of wanting to understand video-game Japanese, and when I am trying to parse some 8-bit era all-katakana chunk of text I find myself wishing it included kanji even though I can only recognize a few dozen just so the grammar is more clear.
Imagine thinking learning ONE phoneme is a hard task... Please never have a look at Arabic or you'll have a stroke.
Moreover [ɾ] can be replaced by [l] perfectly fine and the vowel devoicing is not something you need to do anyway (it's not even occurring in all dialects). So even searching really hard for "difficulties" you can't find even one thing that is remotely difficult which just proves my point.
There are also some other easy things like grammar (very few rules, that are quite consistent and composable) and some basic sentence pattern (heck you can make full sentences, sometimes conversations, with a single word [the predicative adjectives]).