I love to use metaphors in a haiku, but they can be ineffective. A key reason that limits the use of metaphors (as that of analogies) is that, as we will discuss further ahead, haiku by itself is unfinished, leaving it for the reader’s imagination to establish connections among the elements of the scene or event described. Metaphor is in some way a nexus between two elements and it would not leave room for the creation of a link between them by the reader. If we say that “the moon is a pearl”, we are comparing the moon, on the one hand, with a pearl, on the other. The link between both is represented by something they share: the color white. In this way, we are presenting a scene that is completely resolved to the reader, without room for the reader to recreate a sense. This rule, it is fair to say, is many times not followed by the great masters of Japanese haiku, as they occasionally use metaphor and allusion to themselves in a very subtle and natural way, so that they become absorbed by the poem itself. Currently, as we have seen, haiku has diversified in such a way that each one of its schools has its own characteristics and rules, far from the ancient traditional one, both in Western countries as in Japan.
The use of metaphors and analogies is considered perfectly valid by many, as in the case of one of its pioneers: the Japanese poet KakioTomizawa (1902-1962), who begun using metaphor, analogy and abstraction on his haiku, influenced by western poetry, particularly symbolism. Influenced by him, young poets started the “Shinko Haiku” (new and young haiku) movement, and rejected in time the use of “kigo.” As for the use of personal pronouns, that is to say, establishing the presence of the poet, or of others, in haiku; even when the general rule is to avoid them, it does not represent an absolute prohibition. In this sense, the reference to the first person is used, whenever the poet is included in the event that is described by the haiku, as part of it, and not as an observer dividing the scene in a within and outside. Many haikus considered models of its genre, include the poet or reference the second and third personal pronouns, but always carefully diffusing him, and not centering the scene in the human being, but including him as a part of it.