It´s a real, "live" shinken. It was forged as one piece. This sword is from the 15th century. Who would have used such a massive sword? What was the size of the samurai who used this sword for battle?
Think how awesome it would have been if it was wielded by some huge 8ft samurai with gigantism and legend around a nearby town is that if you slay the giant, you get to keep his sword as proof.