Frequently Asked Questions

Why do you use “Kouan” instead of “Koan?”

This is a question we often get, not only about Kouan specifically, but about how we’ve decided to romanize several of the Sailor Moon character’s names. Please know that there are many different ways to approximate Japanese sounds. There is no best way and it is often up to personal preference. We like to go back to the original root word of names that the Japanese sounds approximate.  Below is our explanation for Kouan, as well as others that have been asked about.

You can also read more about Character’s names and their possible origins over on our Name Origins page.



The Four “Ayakashi” Sisters (Ayakashi was translated as Supernatural because it is the most fitting translation to us) individual names are derived from the names of minerals, however, this is where people often get confused. The names are derived from the Japanese names of the minerals rather than the English. Three of the mineral names (Berthier, Calaveras, Petz) take the original roots of the English word and change into regular Japanese mineral naming. 

Berthier —-> ベルチェ鉱 Beruchekou 
Calaveras —-> カラベラス鉱 Karaberasukou
Petz —-> ペッツ鉱 Pettsukou

The English for these are Berthierite, Calaverite and Petzite. Each takes another word and adds the suffix -ite. You’ll notice that the English is happy to take letters away to stop it sounding odd, for example, Calaverite rather than Calaverasite. Berthierite is named for Pierre Berthier, Petzite for W. Petz and Calaverite for Calaveras County in California.

Anyway, the Japanese names (there are several different ways of calling minerals in Japanese, but we are referring the common addition of -kou), do not remove the sounds and match up relatively well, as well as the two languages can. So Beruche = Berthier, Karaberasu = Calaveras and Pettsu = Petz. 

Kouan is different. She comes from a mineral that never came in through English. The trend in naming is the same in Japanese, but it changes in English, as there’s no root English word to match. It comes from the mineral 紅安鉱 kouankou (The English word for Kouankou is “Kermesite” which is etymologically unrelated). We have just taken off the “-kou” (which makes it a mineral name) as we have for the other three sisters. However, the issue is that Kouan’s name is written in Katakana–the Japanese system of syllables usually reserved for loanwords. The key word is USUALLY. Do not think just because a word is in katakana it must be a loanword. Anyway most of the time the sound “ou” in Japanese is the same as “oo”, though there are exceptions. This, however, is not one, so rather than コウアン (Kouan), the “u” becomes a held down vowel (Ko-an). This is the point of confusion, do you romanise the character’s name directly or not? Its up to the translator. 

Hence you get Koan, Kooan and Kōan, none of which are incorrect. We’ve also seen  “Cooan” which does not really approximate much but represents the sounds correctly so none of these should be regarded as incorrect. Feel free to use any that you are comfortable with.

Regardless rather than directly romanising Kouan’s name in katakana, we have pulled back to the original word and romanised that instead, so her name is derived the same way as her other sisters and matches better. So we do not end up with Karaberasu, Beruche, Pettsu and Koan. We are approximating the words for an English audience after all.