To facilitate preschoolers' emotional development, it is useful to have a developmentally and culturally appropriate measure of emotion knowledge. The Affect Knowledge Test (AKT), a widely used measure of emotion knowledge, has been previously used with diverse cultural groups, including Japanese preschoolers, despite scarce reliability and validity information. Thus, the purpose of the present study was to conduct field tests of the Japanese-translated version of the AKT and a preliminary psychometric evaluation of the measure with Japanese preschoolers. Initial analyses of the Japanese-translated version of the AKT showed that the emotion recognition scale had a low internal consistency and subscales were hardly correlated with each other. After emotion faces used in the AKT were modified based on the interdependent cultures' attention bias in emotion decoding, both reliability and construct-related validity were improved to satisfactory levels. These findings highlight the importance of cross-cultural adaptation of measures and demonstrate preliminary validity evidence for future adaptation of the AKT with Japanese preschoolers.