Talk:Internet Co., Ltd./@comment-36872111-20181208034703/@comment-4946341-20181208055916

Did a little digging, looks like it's found here on Amazon Jp:

https://www.amazon.co.jp/%E6%8B%9D%E5%95%93%E3%80%81%E3%81%82%E3%81%AA%E3%81%9F%E3%81%AF%E3%83%9C%E3%83%BC%E3%82%AB%E3%83%AD%E3%82%A4%E3%83%89%E3%82%92%E7%9F%A5%E3%81%A3%E3%81%A6%E3%81%84%E3%81%BE%E3%81%99%E3%81%8B-%E5%8C%97%E6%A2%9D-%E4%BF%8A%E6%AD%A3/dp/433151630X,

You would likely need a proxy service to order it and it is most likely fully in Japanese. It's Japanese title is "拝啓、あなたはボーカロイドを知っていますか?"