Sound symbolism is a linguistic feature that may suggest a non-arbitrary link between sound and semantic content that has been shown to play a role in language acquisition, and potentially language evolution. One sound-symbolic structure known as phonesthemes has been identified in many languages. Phonesthemes are sub-morphemic sound patterns associated with specific meanings more frequently than chance. Cognitive approaches to phonesthemes typically rely on a known example. Phonesthemes are not well attested in Japanese, so this approach is not an easy option. This research provides a route for research into the cognitive effects -- in particular language acquisition -- of Japanese sound symbolism. I present a model for identifying phonestheme-like features in Japanese adapted from a model originally used with English and identify two candidates in Japanese. I also outline methods for empirically testing the psychological reality of these clusters based on existing English and Japanese sound symbolism literature.