@Override
	public String filter(String original) {
		String normlized = normalizePartOfRomanization(original);
		StringBuilder sb = new StringBuilder(normlized.length() * 2);
		for (int i = 0; i < normlized.length(); i++) {
			char c = normlized.charAt(i);
			if (12449 <= c && c <= 12534) {
				sb.append(romanArray[((int) c - 12449)]);
			} else if (c == 12540) {
				// 長音をスキップ
			} else {
				sb.append(c);
			}
		}
		return sb.toString();
	}