Type backslash more easily on Japanese wireless keyboard
I was able to download and use Ukulele from http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&amp;item_id=ukelele  however while the software seems powerful it's far from easy to use and have keyboards install. The manual is lengthy and takes a while to go through. There's no quick way of fixing things, unless you have a lot of experience I guess. The keyboard layout I created seems to work in Notes, but it does not work in Google Chrome (I couldn't write this comment using it) 

Ok so I restarted Google Chrome and can now use the keyboard layout. Seems to work, look \\ :-)

And to add something... Ukulele works on an inherent feature of OS X (the keyboard layout files), just adds an UI on top of it. It would be nice with a simpler solution so if anyone knows feel free to add an answer.