Style is the element of writing which is most personal (as opposed to, say, content, which is largely shared, and no more so than in traditional haiku). Priest and poet Issa employed a folksy, empathetic style to suggest his own persona as well as to attract sympathetic readers. He was the first to employ the cult of personality in haiku. By way of proof, consider the following two poems:
Don't be beat,
Issa is here!
Don't be beat,
Jim is here!
One of these poems is greeted sympathetically, the other with howls of derision, as is mete. It is clear the signifier "Issa" connotes hope and connection, while the signifier "Jim" does not. This is not solely because of content: "Jim" has written many haiku which are empathetic with natural beings and forces, but the aggregate of his work does not suggest the level of identification which earmarks Issa's haiku. And, presuming the forces of identification are no greater for the one than the other, it must be the residue of persona(lity) which accounts for the difference in readings. This is hardly a debunking of Issa, rather an appreciation of the success of his strategy, which moreover continues to win readers two centuries after his death, while marking out a literary turf which, as we've seen from the counterexample above, makes intruders seem laughable. Few authors in any genre have so successfully created a brand with such a loyal following, and preserved it for such a length of time.
It is my further contention that Issa filled the formal structure of haiku with the content of tanka, but I've used up my allotted spaceback