Start with two square sheets of paper
Fold each sheet in half to make a rectangle
Unfold both sheets
Fold each sheet in half the other way to make a smaller rectangle
Unfold both sheets
Fold the top and bottom edges toward the center crease
Fold each sheet in half along the center crease
On one sheet, fold the left end diagonally upward
On the other sheet, fold the right end diagonally downward
Flip one folded piece over
Place the two pieces at right angles to each other
Tuck the ends of each piece into the pockets of the other piece
Tighten the folds so the star locks together
Flatten the ninja star carefully