A single juvenile pomacentrid specimen (5.9 mm standard length) was collected from the Korea Strait in October 2010. The specimen is characterized by punctate-stellate melanophores scattered on the operculum and dorso-ventral region in front of the caudal peduncle, the lack of melanophores on the posterior end of the anal fin base, the presence of 14 spines and 14 soft rays on the dorsal fin, and the presence of 2 spines and 12 soft rays on the anal fin. A molecular analysis based on mitochondrial DNA 16S rRNA sequences showed that this specimen is closely related to adult Chromis mirationis (d = 0.002), but that it differs from Chromis notata (d = 0.017). Juvenile C. mirationis differ from juvenile C. notata in having no melanophores on the posterior end of the anal fin base. We propose a new Korean name, "tti-ja-ri-dom" for C. mirationis.