Peter, I'd agree that one person would be best, but if the girl closest to the camera were the one person, what the picture would say is: "Brrrr."
Thanks for taking the time to discuss about this image, I am flattered!
Allow me to jump in and say a word about intend and process:
- I took first the same image without people in the foreground, and that was the initial intend (this was shot on tripod),
- I did then wait deliberately for some potential onsen users to show up and did capture a few, out of which the one I posted is my favorite because I feel it does tell a story about cold, about girls hesitating a bit about entering naked a mixed onsen with some man already inside.
I agree that they relative position is not perfect, but this is not a posed image...