KANAI Norishige was born in 1976 in Tokyo and then brought up in Chiba. He graduated from National Defense Medical College in 2002. After graduation, he worked as a surgeon and a Diving Medical Officer at Japan Maritime Self Defense Force.

He was selected to be an astronaut candidate by Japan Aerospace Exploration Agency (JAXA) and joined JAXA in September 2009.
He was certified as an ISS astronaut in July, 2011. From December 2017 to June 2018, Kanai stayed in space for 168 days as a flight engineer for the ISS Expedition 54/55 mission. He carried out various experiments for both JAXA and international partners, notably a small animal rearing mission under his mission theme "Discovering clues about health longevity in space.", as well as a Extravehicular Activity (EVA) and capture of a Dragon cargo spacecraft (SpX-14) by maneuvering the Space Station Remote Manipulator System (SSRMS).