Sadio Mane had opened the scoring for the African side after a clanger from the Japanese goalkeeper.
However, Inui got his team-mate out of trouble by equalising for the Asian nation in the 34th minute against the run of play.
Beating the offside trap, Yuto Nagatomo burst into the box and slipped the ball to Inui who then curled a low shot past a couple of defenders and into the bottom corner from 15 yards.
A draw from both teams would bring them onto four points ahead of the second Group H match between Poland and Colombia later.
June 24, 2018