Ancient writers, including Socrates and the Upanishads, argued that sibilants are associated with the notions of wind, air and sky. From modern perspectives, these statements can be understood as an assertion about sound symbolism, i.e., systematic connections between sounds and meanings. Inspired by these writers, this article reports on an experiment that tests a sound symbolic value of sibilants. The experiment is a case study situated within the Pokémonastics research paradigm, in which the researchers explore the sound symbolic patterns in natural languages using Pokémon names. The current experiment shows that when presented with pairs of a flying-type Pokémon character and a normal-type Pokémon character, Japanese speakers are more likely to associate the flying-type Pokémons with names that contain sibilants than those names that do not contain sibilants. As was pointed out by Socrates, the sound symbolic connection identified in the experiment is likely to be grounded in the articulatory properties of sibilants – the large amount of oral airflow that accompanies the production of sibilants. Various implications of the current experiment for the sound symbolism research are discussed throughout the article.