Key to this is that Kai said engineers have already developed a standard transmission, and "there is hardware ready." That hardware will clearly fit right-hand-drive Supras, Kai declaring that such a model "needs to be sold in Japan." After that, the situation gets fuzzy. If Toyota spent the money on creating a manual for RHD markets, it seems logical that they'd spend the comparatively much smaller sum to rearrange the necessary components for LHD markets, too.
However, the big spend is in compliance and mass production, which is apparently what gives Toyota pause. As Kai said to RT, "If, for example, U.S. customers are demanding strongly that Supra needs to be a manual-transmission car, then we will plan it."
Based on comments at Supra forums and on a legion of car sites including this one, it's difficult to believe Toyota wonders whether U.S. customers "are demanding strongly" a manual gearbox. On the other hand, Toyota has to think about what happens once it has fulfilled orders for all the old-timey Supra lovers; what will the manual take-rate be for the younger buyer fresh to the Supra fold?
Toyota already has limited- and special-edition Supras in mind, Kai telling RT the development teams must have plans "to introduce something new quite frequently, otherwise a car can lose interest." That could provide a potential route to a manual, with perhaps the carmaker releasing a special edition of "a few hundred cars."
Yet, without setting a bright line on how much feedback or how many deposits on a stickshift would be needed to compel manufacture, a row-your-own Supra remains in the folder labeled "Keep Dreaming." While hardcore owners pretend as best they can with the eight-speed automatic, know that there is a more hands-on solution out there, likely being hooned by a unicorn and a ManBearPig on their way to the Cave of the Winds.