Would i be right in saying that it has been searching for the light due to its leaning habbit, has something been removed just at the back of it? yes you can prune pieris.

Yes, it is leaning out from a wall which is north facing.

They respond surprisingly well to quite hard pruning - just confirmed this in practice.

I agree,it needs a good pruning..is it planted in ericaceous compost,Marcus? they do prefer it,so maybe you could dig some in .or top it up with a good mulch..one of mine is planted in a north facing position by a wall too,but it seems to prefer being shaded..good luck ,I'm sure it will thank you in the long run :o)