Welcome to e-budo Shaina,
This dojo is teaching Nami Ryu. This art is James Williams' amalgam of the arts he has studied. Having not studied it, I can't say whether it is effective or not, but Mr. Williams has studied with some very good instructors. It is NOT a traditional Japanese art, although I believe he follows a lot of the traditions of the koryu. The only other Japanese sword art that I know of in Fresno is Morinaga-ha Toyama Ryu.
My advice would be to go and check it out for yourself, and see what it is like.
Cheers,
Paul Smith
"Always keep the sharp side and the pointy end between you and your opponent"