With Hariwake, one of the most important factors is wheteher it is clean.(No black) This one looks very clean, although I can not see the face properly, and that is where black often appears.
However, the Hariwake has a very weak pattern/almost scattered, and not interesting, and might loose it.
The intensity of the metallic is also very important on a Hariwake, but difficult to judge on a photo.
This one is a bit small considering that it is probably a local bred from last year season. It means that it is probably already 1 year old, and only 15cm.
Growth rate in the first year is a very important factor to look at when judging a koi. If it was for instance in a small dealer tank for a long period of time, it will very seldom grow very large.