This origami is made with one piece of paper. How quaint!
Fujimoto’s Hydrangea is constructed iteratively. You begin with the largest set of petals, and then work your way inward, adding successively smaller sets of petals. Here, there are four sets of petals, but potentially you could add more. But it’s limited by the thickness of the paper. I first attempted this using small pieces of paper, and could only reach three iterations; by using much larger paper, I could only achieve one additional iteration. The finished model is about 15 cm wide.
Folding instructions can be found free on the internet. Although, I would rate this one as moderately difficult.