Here Is how to make a wooden ninjato prop for movies. It is all one piece, and it is made of durable pine wood. The difference between most japanese swords and the ninjato is that the ninjato is flat, while others are curved.

MATERIALS:

A long pine wood 1" X 24" rectangle

Black duct tape

Silver spray paint

A saw

Step 1: Cutting to Size

The great thing about this project is that it has adjustable lengths. I used about 1 1/2 feet.
To start, cut your wood to a length you'd like. Here comes the hard part. Cut a diagonal mark from the top corner to about an inch down. That is the sword' tip.

Step 2: Hilt and Blade

The way to make the hilt is to measure how long a space you need to hold it with two hands. Then wrap that area with black duct tape. Spray paint the blade silver.

Step 3: Finishing Touches

Add a dragon or lion design. I added as dragon in thin sharpie marker. Golden paint markers work.
The guard is not too hard. Cut out some cardboard, spray paint it, and cut a hole in the middle so it fits around. Add some hot glue for durability.

I could also make a sheath. Post in the comments BELOW and I will get back to you.