Changing defaultLocale to jp-JP in local.json is not working

[hawaiiden]

Prerequisites

• I am running the latest version
• I checked the documentation and found no answer
• I checked to make sure that this issue has not already been filed

Information

I tried to change language and currency of my VS, so I edited i18n in local.json
like this,

"i18n": {
      "defaultCountry": "JP",
      "defaultLanguage": "JP",
      "availableLocale": ["en-US","de-DE","fr-FR","es-ES","nl-NL", "jp-JP", "ru-RU", "it-IT", "pt-BR", "pl-PL", "cs-CZ"],
      "defaultLocale": "jp-JP",
      "currencyCode": "JPY",
      "currencySign": "円",
      "currencySignPlacement": "append",
      "dateFormat": "l LT",
      "fullCountryName": "Japan",
      "fullLanguageName": "Japanese",
      "bundleAllStoreviewLanguages": true
    }

Every locale is working except jp-JP, which is above way.
The error message is,

Error during render : /error
{ Error: Cannot find module './jp'
    at server-bundle.js:26736:12
    at process._tickCallback (internal/process/next_tick.js:68:7) code: 'MODULE_NOT_FOUND' }
(node:40996) UnhandledPromiseRejectionWarning: Error: Cannot find module './jp'

1. If there is better way to change language and currency of VS, please let me know.
2. Why only Japan option is not working? Is this normal or I did something wrong? or should I install anything like Japanese language module?

[pkarw]

Fixed by #3831