First, shape the ketchup rice into rounded triangles.

Next, fold the nori in half and press a round cutter onto the nori to make an impression.

Once you have the impression, cut along it with scissors.

Then, use the same round cutter to cut circles out of the sliced cheese.

Next, use a wide straw (like a bubble tea straw) to cut smaller circles from the cheese.

Layer the cheese and nori circles to make the wheels.

Use a toothpick to cut out windows from the remaining cheese.

Place the wheels and windows onto the rice balls.

You're done!