What is this plant?

This is a little plant that the landscapers dug up yesterday to put in the new plantings.  I hadn't paid any attention to it because I thought it just a dead little stump so I was thrilled to see one full-blown flower, several leaves and a scattering of buds.  I want to replant it.  What is it?



here's what the poor little stump looks like

 


double pink petals, about 2" across

 

Later...  Rhododendron???  Maybe "azuma-kukami"?

But...  to me, it looks way too flat-backed to be a trumpet shape, and there's only a single thingie coming out of the middle (stamen? pistil?).