How to make an origami menko out of single square paper

(page 7)

11th picture of origami menko out of single square paper

11.

Apply the horizontal "valley-fold" of the step #10 and then unfold.

Prepare to rotate the paper by 90 degrees.

12th picture of origami menko out of single square paper

12.

Rotate the paper by 90 degrees.

Prepare to apply a horizontal "valley-fold" and then unfold.