'R', 'L', and Other Points of Pronunciation
I spoke to a Japanese native at my church because I was a little confused. Why is Sango's demon cat's (in Inuyasha) name spelled "Kirara" but clearly pronounced "Kilala"? Why the big deal on the net over "Malik" vs. "Marik"? Why? Well, I have a halfway decent explanation. The letter "R" in Japanese is rolled. In names it is often rolled a lot, so much so that it beings to sound like an "L". It's kind of like if you say my name Anne-dree-ah or Ahn-drey-ah. Since the word looks like "Kirara" but sounds like "Kilala" the dubbing company has two choices, they can say it the way it is spelled, or they can say it the way it sounds. Since we rarely ever see the name spelled out, many opt to simply say it the way it sounds (as in Inuyasha). But others (like YGO) chose to say it how it is spelled to avoid confusion. Thus, though "Marik" sounds like "Malik" is the Japanese, it truly is "Marik" just with a severely rolled "R". And, lets face it, us English speaking peoples have never been the greatest with rolling our "R"s. So, neither is wrong.
This is becoming an increasingly large source of discontent in the fan community as English translators move more and more towards keeping the original Japanese names in popular series. I have seen more than one rant on how "Raito"s name was changed to "light" in the English version of Death Note, and I've even seen a commentary on the Legend of Zelda with "Rinku" vs "Link". I want to point out that these are not "changes" in names, or replacement of "perfectly good, original Japanese names". It is simply Romanization of the written Japanese, and it is quite often confusing for English speakers. The kanji pronounced by Japanese speakers as "Raito" really is written in English as "Light", and the same is true of "Link". The only proof I can offer you is this - give a native Japanese speaker the English word "Light" on a piece of paper, and I guarantee they will read it aloud to sound something like "Raito", give them the English word "Link" and they will read it aloud as "Rinku". It all goes back to 'R' and 'L' and the way they end their consonants.
So... if you ever read that the letter "R" doesn't exist in Japanese, or doesn't have it's own sound, this is untrue. Karate really is karate and sayonara really is sayonara. It's only in names that we have issues. And even then it is not consistent, after all, Miroku is Miroku (with the r sound) even in the Japanese. It's all a matter of degree.
As for the rest of Japanese pronunciation, generally two vowels together each get their own sound. If it seems as though it isn't, that's because one of the letters is getting its sound for a very short time. Try it sometime "Aishiteru" really is "Ah-iy-shiteru", it's just that the "Ah" is very short. Kaoru really is "Kah-oo-ru" it's just that the "ah" is again very short. They are what we call diphthongs in English, two distinct different sounds meshed until our brain considers them one sound.