The art of folding paper is called origami 折り紙 - ori "folding" and kami "paper."
To make the hydrangea flower, we start with a square piece of paper, which we fold on both diagonals.
Then in the middle, like so:
Placing the colourful side inside, we fold the paper to form side squares.
The free parts are oriented downwards.
Repeat on the four sides, and now the folded paper should look like this:
Turn it and fold as in the following photo:
Then open the petals:
It should look like this:
Ajisai pattern is common in summers, like on the yukata I received from a special friend. I am greatful for this beautiful present.
I cut the origami into 16 tiny squares and made a small ajisai, and a snail. :-)
Italian Polka by Rachmaninoff inspired me. Though it represents festive nature, it makes me hear drops of rain. And I associate rain with hydrangea. Anyway, it is a refreshing song on a hot summer day.