We report the discovery of 10 supernova candidates from a transient survey with Subaru/Hyper Suprime-Cam (HSC). Our Subaru/HSC open-use observations were performed on 19 Aug 2015 UT, under poor weather condition with 1.1-1.5 arcsec seeing. The candidates were detected in real time using a quick image subtraction system (ATel #6291). Candidate screening was performed by incorporating machine learning techniques into the system. The reference images were obtained with HSC on 2 and 3 Jul 2014 UT.