((Update)) It was not optional for me. I did not have a choice! But you don't have to do all corrections though.
I had an account with livemocha.com and was surprised I could not start learning straight away. That was my first surprise. I had to correct people homework who wanted to learn my native language. And when I started at least learning, it was flash cards, not the course. You just learn some vocabulary or phrases such as "He is old", "She is small." "The bag is on the table." You cannot download anything. And you need to know how to read and write already. Hopefully they will use the transliteration. But I doubt it. It was not my experience. Also when I was correcting people's homework, I spotted some faults of vocabulary. In addition, they started to add this page after I had completed a unit, or an exam about sharing with my friends on Facebook. Then I had to pay if I wanted to get the real course, or to make some advertising to Facebook to bring at least 3 friends to livemocha.com
So after a while I gave up and went to other websites who don't claim to be "free" but are free.
If you want a similar initiation try the Byki Express download flash cards. That is very good for a start and to give you an idea. Beside it is entirely free! http://www.byki.com just type in your email address, but nothing else, and untick all boxes to get your download.
For real free download courses:
1) http://www.archive.org/download/Fsi-JapaneseFast-StudentText/Fsi-JapaneseFast-StudentText.pdf
2) http://web.archive.org/web/20030812083805/languagelab.bh.indiana.edu/online.html (PDF course)
3) http://grammar.nihongoresources.com/lib/exe/fetch.php?media=an_introduction_to_japanese_-_syntax_grammar_language.pdf
4) http://www.eric.ed.gov/PDFS/ED053623.pdf
5) http://ankisrs.net/ (Check the video tutorial to know how it works), and once installed click on Download to browse the list of shared decks. Type in Japanese. And download the free flash card or deck). After you need to click on File, Download shared deck to browse the list.
For free lessons online or flash cards vocabulary:
1) http://www.nhk.or.jp/lesson/english/learn/list/index.html (100 free lessons pdfs, and each audio lesson can be downloaded individually for free but not as a group).
2) http://www.internetpolyglot.com/lessons-en-ja
3) http://japanese.about.com/od/writing/u/Writing.htm#s1
4) http://www.easyjapanese.org/write_hiragana.html