Sagi was born in the coastal city of Hadera. During his childhood he used to draw with a black pen a flow of endless associations of images on any surface that came his way. When he was 18 he joined the IDF. During his service he was stationed as a combat soldier in Field Intelligence. Out of bushes and shrubs he spent three years watching and observing the Palestinian people. The movie Eli he created together with Reut Elad as part of the final project for the Art Academy Bezalel.