Beautiful image. To me it's a Sparrowhawk. Juvenile Japanese Sparrowhawk always resembled a young Cooper's to me with the teardrops rather than the chevrons.
Satish, no I don't have any pics showing the differences. Going on memories of seeing Japanese Sparrowhawks in England in the old days where you could import anything from anywhere. I remember walking into a shed in Yorkshire and it was full of Shikras and another was full of Lanners. You could try googling them and see if that helps.