The only disappointment of the day was wrestler Babita Kumari losing 1-5 to Greece's Maria Prevolaraki in the women's Freestyle 53 kg 1/8 Final.
All eyes were fixed on star shuttler Sindhu, who on Wednesday defeated World No. 2 Wang Yihan to set up her semi-final clash with world No.6 Okuhara.
World No. 10 Sindhu continued with her giant-killing spree as she made light work of the Japanese to register a 21-19, 21-10 triumph in the semi-finals and become the first Indian shuttler to enter the final of the Olympics.
With this win, double World Championship bronze medallist Sindhu improved her head-to-head record against reigning All England Open champion Okuhara to 2-3.
In the final, she will face two-time reigning world champion Carolina Marin of Spain, who beat defending champion Li Xuerui of China 21-14, 21-16.
Irrespective of the colour of the medal in the final on Friday, it will be India's second medal in the Rio Games after wrestler Sakshi bagged a bronze medal in the women's 58kg category.
Sindhu's height and long reach gave her a lot of advantage against the pint-sized Okuhara, who also had her right thigh strapped.
Especially, Sindhu's sharp cross-court game and half smash helped her get off to a fine start as she took the first game 21-19.
In the second game, Sindhu turned more aggressive and played a fearless game to stun the Japanese who looked short of ideas.
The 21-year-old Hyderabadi kept earning points, hitting one smash after another to enjoy a comfortable ride. As many as 10 points on the trot catapulted her to the final with a 21-10 win in the second game.
Afterwards, what followed was a screaming celebration from Sindhu and her camp.
Earlier in the day, grappler Babita's dreams of an Olympic medal shattered after losing to Greek Maria Prevolaraki in the women's Freestyle 53 kg 1/8 Final.
Babita struggled to find her feet in the first period after being pushed out of the safety zone and then the Greek wrestler took another two points to extend the lead further to 3-0.
The 26-year-old Indian managed to bag a point in the second period as Maria failed to make the most of the 30-second advantage.
Babita once again went for aggressive play but Maria turned it around to add two more to her score. From then on, things started slipping from the Indian's hands as Maria displayed great defensive skills to hold on and beat the Indian 5-1.
Meanwhile, on the golf course, India's Aditi Ashok, whose second round is currently underway, is tied sixth.
