Complex sentence: Presumably it was in Japan that he met Ms. Eisei Toshiyori; their daughter Iva Matrix accompanied Irving through most of his public life, acting as assistant and manager in most of his enterprises.
Split into simpler sentences: Presumably it was in Japan that he met Ms. Eisei Toshiyori. Their daughter Iva Matrix accompanied Irving through most of his public life, acting as assistant and manager in most of his enterprises.