Interesting detail:
The wound on the heart becomes larger at the start of every new volume.
The distance between the two persons running also becomes larger.
And looking the legs, it seems that they represent a child chasing an adult.
Now only the child is left running, with the adult no longer being seen.
Perhaps the one who those legs represents is Haruno. And the absence of the adult's legs shows how he's now chasing after someone who is no longer there.
