Many people overthink hokku. Once one understands the aesthetics, it becomes quite simple.
Here is a summer hokku:
A summer shower;
All over the river —
It has no hidden message. It expresses the season in a natural event, without any commentary or interpretation, and without any “self” of a writer appearing. A shower has begun, and everywhere on the surface of the water are the widening circles caused by each raindrop as it touches the surface.
It is a simple experience of the senses, not of the intellect.
If we use our old “setting/subject/action” pattern, we can look at it this way:
Setting: A summer shower
Action: Widening all over the river
Now you can see that these elements are not arranged precisely in order in the hokku, but they are there nonetheless. The setting/subject/action pattern is just a helpful tool in composing, not a rigid group of boxes into which each element must be forced in a strict order.
All one needs to write hokku is to realize that it is not a conventional “poem.” It is an experience of the senses that is felt to be meaningful, involving Nature or the place of humans as a part of Nature, set in the context of the seasons, and devoid of ego and added commentary. Hokku uses ordinary words and ordinary things, but in these we should feel a sense of significance that is beyond explanation.
Of course hokku has its own aesthetic of simplicity and selflessness, and always in the background we feel that universal characteristic of existence — impermanence, the transience of things. In this hokku we see it in the circles that appear, widen, and vanish on the surface of the river.