elasticsearch/docs/reference/elasticsearch-plugins/analysis-kuromoji-readingform.md

mapped_pages
https://www.elastic.co/guide/en/elasticsearch/plugins/current/analysis-kuromoji-readingform.html

kuromoji_readingform token filter [analysis-kuromoji-readingform]

The kuromoji_readingform token filter replaces the token with its reading form in either katakana or romaji. It accepts the following setting:

use_romaji

Whether romaji reading form should be output instead of katakana. Defaults to false.

When using the pre-defined kuromoji_readingform filter, use_romaji is set to true. The default when defining a custom kuromoji_readingform, however, is false. The only reason to use the custom form is if you need the katakana reading form:

PUT kuromoji_sample
{
  "settings": {
    "index": {
      "analysis": {
        "analyzer": {
          "romaji_analyzer": {
            "tokenizer": "kuromoji_tokenizer",
            "filter": [ "romaji_readingform" ]
          },
          "katakana_analyzer": {
            "tokenizer": "kuromoji_tokenizer",
            "filter": [ "katakana_readingform" ]
          }
        },
        "filter": {
          "romaji_readingform": {
            "type": "kuromoji_readingform",
            "use_romaji": true
          },
          "katakana_readingform": {
            "type": "kuromoji_readingform",
            "use_romaji": false
          }
        }
      }
    }
  }
}

GET kuromoji_sample/_analyze
{
  "analyzer": "katakana_analyzer",
  "text": "寿司" <1>
}

GET kuromoji_sample/_analyze
{
  "analyzer": "romaji_analyzer",
  "text": "寿司" <2>
}

1. Returns スシ.
2. Returns sushi.