From Isao Tomita's Facebook page:
"Isao Tomita, composer and synthesizer artist, died May 5, 2016 of chronic cardiac failure at 2:51 p.m. at Tokyo Metropolitan Hiroo Hospital. He collapsed around noon in his home and was taken to the hospital, where he passed away with family at his bedside.
Private funeral ceremonies attended only by family took place on May 7th and 8th.
We announce this news with great sadness.