Your question should be answered by an official of the Mikubook site. As stated, the contributors of this wiki are not the developers of third party software.
- In an attempt to answer
Since the sites name seems to be a play on the word Face'book and its purpose is to spread music, it is unlikely you will be able to access the site without a Facebook or Twitter. But once again, please contact the creators of Mikubook to see if there is an upcoming update that doesn't require social network connections.