How to create a Japanese last name?

I'm writing a character for my story and wanted to know how to make a given name and family name. The words i wanted to use are "Freedom" "Power" and "Joy" and would like to make a name on those.

If your goal is for the same to sound plausible, you might want to trim the name from three themes to two. Most Japanese family names are made of two kanji characters, and while there are some with three, having an unusually long name that's also got a dramatic meaning is probably going to feel a little over-the-top, and maybe even distractingly so.