What is a tato? In his book Complete Origami, Eric Kenneway says
A tato is a traditional kind of folded paper purse in which a Japanese housewife keeps small items such as needles, ends of thread, buttons and so on.
The simplest tato of all is a square, folded so that it has what I think of as a “box closing” on the top. The sides are folded in rotation so that they lock the tato shut.
Start with a square of paper. Mark the mid point on two sides by folding in half and gently pinching the fold to make a mark halfway up each side.
Fold the bottom edge up to the mark and crease the fold.
Fold the top edge down to the middle and do the same.
Open your paper, rotate 90°, and repeat all the steps above with the new top and bottom edges. Open your paper flat again.
Fold the bottom edge up to the middle, then fold the right edge in to the middle.
Fold the top edge down to the middle.
Fold the left side in to the middle.
Now it gets a bit tricky: the lower part of the last section you folded has to tuck under the layer at the bottom. Rotate your tato 90° clockwise so that the last fold is at the top. Lift the edge up, pull the left corner out and to the left, then start to push the upper edge (pink pointy finger) back down to the middle.
As you are pushing down, you must also push the left edge toward the middle, easing the left edge of the top flap (pointy finger) under the bottom flap. You may find this difficult the first time you try it, but it’s one of those things that gets a lot easier with practice.
Your finished tato should look like this.
You can make your tato out of patterned paper.
This paper design is currently being offered by Paper Kawaii.
You can also find a photo tutorial for a second simple square tato on Paper Kawaii. Use the arrows at the sides of the tutorial images to navigate through the pictures of the steps. I made the centre square a little larger in mine.
These would work well as the top layer of a Zhen Xian Bao, or they could be glued into a book to act as pockets for small items.