Seven specimens of the sharpbelly Hemiculter leucisculus (Basilewsky, 1855) were collected by angling from a stream connected to the Hyakken River emptying into Kojima Bay, Okayama city, Okayama Prefecture, western Honshu, Japan, on 19 July 2016. This collection represents a new Japanese record for the species as an alien fish. The specimens are identified based on their morphology and genetic analysis of CO1 of mitochondrial DNA. One of the sequences of CO1 from six specimens is accorded with a previously reported haplotype H2, and that from the remaining one specimen has a newly obtained haplotype (H5) close to H2. Although the species has not yet been confirmed for its establishment in the stream, some individuals were found on the sampling date to jump out of the water, and this behavior resembles one associated with the spawning of the species observed in China. It is necessary to monitor the species in the stream and adjacent waters.This study was partially supported by JSPS KAKENHI grands (no. 15J05777 to M. N. and no. 15K07527 to K. N.