I am studying ultraluminous infrared galaxies (ULIRGs) and active galactic nuclei (AGNs) through infrared, X-ray, and millimeter observation. The main scientif goals are to (1) detect (optically-elusive) deeply buried AGNs in ULIRGs, and (2) understand the AGN-starburst connections in the universe. Please see our press release at the Subaru Telescope.