Example using Kuromoji readingform and NGram

gistfile1.txt

DELETE kuromoji_sample

PUT kuromoji_sample
{
  "settings": {
    "analysis": {
      "analyzer": {
        "hoge" : {
          "type" : "custom",
          "tokenizer" : "kuromoji_tokenizer",
          "filter" : ["reading", "ngram_sample"]
        }
      },
      "filter": {
        "ngram_sample": {
          "type": "nGram",
          "min_gram": 2,
          "max_gram": 2
        },
        "reading": {
          "type": "kuromoji_readingform",
          "use_romaji": false
        }
      }
    }
  }, 
  "mappings": {
    "sample_type" : {
      "properties": {
        "text": {
          "type": "string",
          "analyzer": "hoge"
        }
      }
    }
  }
}

POST kuromoji_sample/_extended_analyze?field=text
{"黒文字のNGram"}

Example Response: 

{
   "tokens": [
      {
         "token": "クロ",
         "start_offset": 2,
         "end_offset": 5,
         "type": "word",
         "position": 1
      },
      {
         "token": "ロモ",
         "start_offset": 2,
         "end_offset": 5,
         "type": "word",
         "position": 1
      },
      {
         "token": "モジ",
         "start_offset": 2,
         "end_offset": 5,
         "type": "word",
         "position": 1
      },
      {
         "token": "NG",
         "start_offset": 6,
         "end_offset": 11,
         "type": "word",
         "position": 3
      },
      {
         "token": "Gr",
         "start_offset": 6,
         "end_offset": 11,
         "type": "word",
         "position": 3
      },
      {
         "token": "ra",
         "start_offset": 6,
         "end_offset": 11,
         "type": "word",
         "position": 3
      },
      {
         "token": "am",
         "start_offset": 6,
         "end_offset": 11,
         "type": "word",
         "position": 3
      }
   ]
}