Impul man Hirakawa will start Sunday's curtain-raiser from seventh on the grid after qualifying 0.631s down on poleman Tomoki Nojiri, as Honda drivers locked out the top four on the grid.
He had been the fastest Toyota-powered driver in Q2, but slipped behind rookies Sena Sakaguchi (Inging) and Ritomo Miyata (TOM'S) in the pole shootout.
Second-placed Toshiki Oyu, who topped pre-season testing at Fuji last week, achieved a best speed of 290.3km/h (180.4mph) during Q3, versus 288.8km/h (179.5mph) for Hirakawa, who said that he was forced to run with less downforce in testing in order to remain competitive.
Revealing he lost time in Q3 with a gear shift issue, Hirakawa admitted that even with a clean run he couldn't have realistically threatened Nojiri.
"It was as expected," Hirakawa told Motorsport.com. "The Honda guys led every session, even in testing, so I was just aiming to be the top Toyota driver.
"After Q2 I was confident, the car felt ok, then unfortunately, I don’t know why, there was an issue with the upshift for Q3. I lost a few tenths there.
"I wouldn’t have challenged the top times but at least I could have been top Toyota… so it sucks."
Comparing the situation on Saturday to last week's test, Hirakawa added: "I was expecting high temperatures and less of a gap between Toyota and Honda but it’s about the same.
"Hotter conditions are better for us. But it’s not enough today, with only 20 degrees [air temperature]. So I’m looking forward to summer!
Honda enjoying a straight line speed advantage over the Toyota runners has been a regular feature of Super Formula in recent years, especially since the switch to one engine per season in 2019.
Hirakawa said he would be satisfied to kick off his season with a podium in the circumstances.
"I think Toyota stopped has developing the engine, so that’s why the gap [to the Honda runners] is getting bigger," said the 2020 runner-up.
"I’ll push to recover in the race. It looks like it’s going to rain tomorrow, and I like the wet. From P7 it will be difficult, but I’ll be happy if I get a podium."
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Ryo Hirakawa, carenex TEAM IMPUL
Photo by: Masahide Kamio