Born and educated in Japan. After obtaining his PhD in astrophysics at Nagoya University, Nagoya, Japan, in 1995, he moved to Europe, working at the Institute of Astronomy, Cambridge in UK (1995-2005), at the Max Planck Institut für Extraterrestrische Physik in Germany (2005-2008), and at INAF-Osservatorio Astronomico di Bologna in Italy (2008-2009). In 2010 he joined ICREA, to work as an ICREA Research Professor at the Institut de Ciències del Cosmos (ICCUB). His main research area is X-ray astronomy on active galaxies and cosmic black holes.