I am primarily interested in understanding the origin and explosion physics of extragalactic transients, particularly type Ia supernovae, by carrying out survey observations with wide-field survey facilities. I am the principal investigator of the "MUltiband Subaru Survey for Early-phase SNe Ia" ("MUSSES"), which focuses on the early photometric behavior of type Ia supernovae discovered by Subaru/Hyper Suprime-Cam (HSC). Recently I am also interested in studying fast transients with days, hours or even shorter timescale by using the first wide-field CMOS camera in the world, the Tomo-e Gozen Camera, mounted on the 1.05-m Kiso Schmidt telescope.