This study developed the Japanese version of the Highly Sensitive Child Scale for Childhood (HSCS-C) and tested its validity and reliability. Data were collected from 400 dyads of primary school children (third to sixth grades: Mage = 9.75 years, SD = 1.22; male = 48.5%) and their mothers (Mage = 41.00 years, SD = 5.05). Two factors were found: the first was the conjunction of Ease of Excitation and Low Sensory Threshold, and the second was Aesthetic Sensitivity. A bivariate correlation analysis indicated that children’s sensory processing sensitivity, measured with HSCS-C, was associated with self-reported empathy and mother-reported temperaments, with both forms being distinct. The internal consistency was found to be satisfactory.