```ruby
class ThunderbirdJa < Cask
  version '24.2.0'
  sha256 'a3e4d03924ee555865b90bb95f8043811e15bfd20358e5b265b5b1cfc4812b7d'

  url 'http://download-installer.cdn.mozilla.net/pub/thunderbird/releases/24.2.0/mac/ja-JP-mac/Thunderbird%2024.2.0.dmg'
  homepage 'http://www.mozilla.jp/thunderbird/'

  app 'Thunderbird.app'
end
```

Upgrade Thunderbird.app (Japanese) to v.31.1.1
user
```ruby
class ThunderbirdJa < Cask
  version '31.1.1'
  sha256 'aa5da47afcc4f71e40f86b94c6033d86d707690a80a8610e1a5f9c09a5ca4629'

  url "https://download.mozilla.org/?product=thunderbird-#{version}&os=osx&lang=ja-JP-mac"
  homepage 'http://www.mozilla.jp/thunderbird/'

  app 'Thunderbird.app'
end
```
assistant