This paper claims that the model of ‘blending’ proposed by Turner and Fauconnier [16, 17] offers a useful tool for understanding poetic creativity in general and metaphors in haiku 1 in particular. It is one of the characteristics of haiku that two or more entities (objects, ideas, and feelings) are juxtaposed by loose grammatical configurations such as kireji (‘cutting letters’) and kake-kotoba (‘hanging words’ or multiple puns). The juxtaposed entities are put in comparison or equation, and contribute to enriching the multi-layered metaphorical meaning of haiku. The analysis of a sample text, a haiku describing a rough sea by Basho Matsuo, demonstrates the effectiveness of ‘blending’ as an instrument for understanding the cognitive role played by (i) metaphorical juxtaposition by kireji and (ii) iconicity of the foregrounded elements in the text.