ケーシー先生のローマ字制度について
Cayce's Romaji System

As I discussed in the previous section, Japanese words written in the Roman alphabet as opposed to in Japanese characters are called romaji. To take something that was originally written in Japanese characters and write it in the Roman alphabet is called romanizing, and the process of doing this is called romanization. There are many systems for romanizing Japanese, and each is useful for a different purpose.  On this website, I use an adapted version of the Modified Hepburn system.  I adopted this method because it clearly shows pronunciation of words to non-Japanese speakers while simultaneously showing those who are studying Japanese how words would be spelled in kana.

In my romanizations, I have also broken up compound words in many places, to make the romanized lyrics more readable for people who don’t speak Japanese.  In some places I have also clumped particles together that technically should be separated, once again I did this in the name of easy readability for people who don't speak Japanese.  So while I have deliberately written my romaji to be helpful to students of Japanese, if you are actually making an honest effort to study the Japanese language, I highly recommend that you try to ignore the romaji as much as possible and focus on the kanji instead.  Kanji are the building blocks of the Japanese language.  I can't stress it enough - the more kanji you learn, the better.

Cayce Modified Hepburn Romaji

I have romanized the particle as “wa.” Though it is spelled with the hiragana letter “ha,” it is pronounced “wa.” 

Similarly, I have romanized the particle へ as “e,” because again, though it is spelled with the hiragana letter “he,” it is pronounced “e.”

I have romanized as “wo” rather than “o” simply because I think it looks better (there may be a few places where I romanized it as "o" instead, if so I'm sorry for the inconsistency). In modern Japanese, this particle is pronounced “o” or "wo" depending on the person, the dialect, and the context.

Instead of inserting dashes or long marks, I have indicated long vowels by doubling the vowels (“aa” instead of “a-” or “a”) because it is more faithful to the way Japanese is written. I have romanized おお as “oo” and おう as “ou” for the same reason.

I have romanized じゃ, じゅ and じょ as “ja,” “ju,” and “jo,” respectively, NOT as “jya,” “jyu,” and “jyo.” Since the syllables are pronounced “jah” (as in “jargon”) “ju” (as in “jujubes”) and “jo” (as in “joke”) I feel that this way of romanizing them is the most easily readable.

I have romanized as “shi,” as “ji,” as “tsu,” and as “zu.” I did NOT write them as “si,” “zi,” “tu,” and “du.” The syllables are pronounced “shi,” “ji,” “tsu,” and “zu,” and only phonologists and fools spell them the other way.  Not saying phonologists are fools, but there's a time and a place for the latter system and it's within the context of phonology papers, only.

I have romanized as either “n” or “m,” depending on its pronunciation in context.