Wow, this thread exploded while I wasn't here.

Anyways, you all are missing one big reason why Japanese romaji doesn't work. It is because the Japanese language is full of syllables, not consonants. There are tons of words that would have only a single letter difference if they were written in romaji. In English if you make a typo for one letter, usually you'd be able to understand the word, but in Japanese if you make a typo - heck, even if you don't make a typo it is hard to read romaji because you need to pay attention to every little letter in order to catch what the whole word is.

The homophones stuff is bull actually. Japanese can (kinda) be used avoiding these homophones, which are all derived from Chinese. Spoken Japanese generally uses more "Japanese Japanese", while written Japanese generally can use more "Chinese Japanese". Writing the pitch accent would be mad though. I don't notice the pitch accent, I know it is there but I don't think about it, it just comes. Most people would have difficulty writing the pitch accent if they had to. That, and the pitch accent is different from the East and the West.

As for the writing system, yea, it is like that, and it isn't exactly ideal, but it is the best you can get I guess.

I personally believe that hangul could be adopted for use with Japanese though, and it could work out quite nicely. When I say adapted, I mean adapted though. You'd have to make a different orthography in order to let each Chinese Character take up one square. Here is an example of my idea:

*disclaimer* This system is far from perfect, and I'm just giving ideas of how it could work. I also haven't even thought about how "Japanese Japanese" would be written in this system, only "Chinese Japanese".

Kanji Hangul Kana Japanese Korean
正直 쇼짘 しょうじき shoujiki syojik
食卓 석탁 しょくたく shokutaku seoktak
限定 겐태 げんてい gentei gentae
発言 핬겐 はつげん hatsugen hatgen
発射 핬샤 はっしゃ hassha hatsya
発表 핬효 はっぴょう happyou hathyo

Hangul has more vowels than Japanese. You can use some of them as the long vowels, and some of the short vowels. In my example, ㅗ is the same as Japanese "ou" and ㅓ is the same as Japanese "o". Likewise, ㅔ is the same as Japanese "e" and ㅐ is the same as Japanese "ei".

Also, you need to put the second part of the character on the bottom, rather than making it written in two blocks like Japanese. Since hangul has more consonants, I can use ㄱ to mean a Japanese "ku" and ㅋ to mean a Japanese "ki". (At the end of a Chinese Character syllable.) In this example I'm using ㅆ to mean a Japanese "tsu".

I'm also trying to keep the spelling as morphophemic as possible. Even though 発射 is pronounced "hassha" and not "hatsusha", I'm still writing the ㅆ at the bottom because it is a part of the character. Readers will be expected to read it out loud as "hassha" even though there is a ㅆ at the bottom. This is the normal way Korean is written as well. However, the next word, you can see is "happyou". This pronunciation is changed quite a bit from "hatsuhyou" that would be read if you read it out normally. I'm still writing it as 핬효 though to keep the morphophemic spelling. Actually I'm still debating over this stuff. One big difference between Japanese and Korean is that in Japanese: h, b, and p are related, while in Korean ㅂ and ㅍ are not related to ㅎ. So using the ㅎ jamo in Japanese is a bit odd. I'll think of a better way to do this one day. I could use ㅍ to represent the h sound in Japanese, but this would drive people who know Korean mad. So the current plan is to make ㅎ related to ㅂ and ㅃ, and not use ㅍ at all.

Uhh, wow. Sorry I hijacked this thread.

So I used some of the Korean vowels to write Spanish diphtongs, two different letters for /l/ and /r/

And then for double letters like "rr" or "ll" which represent a particular sound in Spanish but are easily understandable to any native as two letters repeated, I used the Korean solution for a /l/ sound between two vowels.