icu4c/source/data/locales/ja_JP_TRADITIONAL.txt

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
// Generated using tools/cldr/cldr-to-icu/build-icu-data.xml
ja_JP_TRADITIONAL{
    calendar{
        default{"japanese"}
    }
}