When director Sho Miyake set out to make boxing drama “Small, Slow but Steady,” he didn’t just leave the film’s star, Yukino Kishii, to put all the work in: He hit the gym with her and learned the basics of pugilism.

“We were both amateurs,” he says, during an interview at this year’s Tokyo International Film Festival. “We’d be chatting with each other while we trained, like: ‘That’s difficult, isn’t it?’ or ‘Why do we have to hit people?’ I think we had fun.”

In the film, Kishii plays a fictionalized version of deaf boxer Keiko Ogasawara, who had a short professional career during the early 2010s. ​​It’s an unlikely role for a petite actress better known for comedies and romantic dramas, though the intensity of her performance quickly dispels any doubts.