It was also curtains for world championships bronze medallist B Sai Praneeth, Kidambi Srikanth and Sourabh Verma.
The fifth seed Sindhu clawed back from a game down to notch up a 14-21 21-15 21-11 victory over Ohori.
Sindhu has never lost to the world No.20 Japanese in their 10 meetings so far. Ohori had lost to the Indian last week in the second round of the Malaysia Masters.
The 24-year-old will take on Japan's Sayaka Takahashi, who defeated Saina, in the second round.
Saina, who won this tournament last year before going through a lean patch, lost 21-19 13-21 5-21 to Takahashi in a gruelling 50-minute contest.
The London Olympics bronze medallist had reached the quarterfinals of the Malaysia Masters last week.
World No.12 Srikanth went down to local favourite Shesar Hiren Rhustavito 21-18 12-21 14-21 in a match that lasted one hour and three minutes.
This was Srikanth's second consecutive opening-round defeat this season. He had earlier also made a first-round exit from the Malaysia Masters.
Praneeth, who like Srikanth had also been ousted in the opening round of the Malaysia Masters, lost to the eighth seeded Chinese Shi Yu Qi 21-16 18-21 10-21. Sourabh lost 21-17 15-21 10-21 to China's Lu Guang Zu.
In the mixed doubles, Pranaav Jerry Chopra and Sikki Reddy went down in straight games to the South Korean combination of Ko Sung Hyun and Eom Hye Won 8-21 14-21.