In the unite-menu the <leader> key was set to be a hard coded ",". This is not good.
I add a script into the autoload folder I made. There is a funtion in that file, and it can help to display the <leader> keys in unite-menu accroding to the setting of people.
For example, I'd like to use the default <leader> key, and all the <leader> keys in unite-menu will be displayed to be backslash.