This explains why Kwok-kwan (who, after two Ip Man films and 2008's The Legend of Bruce Lee series, is as synonymous with the role as Yen is with Ip) is mostly absent, while Ip tries to navigate a nation that doesn't understand what martial arts are ("Like a gymnast?" one American school principal asks in bafflement as Ip explains that he, too, is a teacher). Ip, like his late wife, has cancer and is starting to think about his personal legacy.
Yet Lee's request is one of multiple spurs to bring Ip to San Francisco – the other being a need to find somewhere safe for his son, who will soon be an orphan. The last film felt like the end, with the death of Ip's wife and a passing of the torch to his greatest student, Bruce Lee (Kwok-kwan), but he's back for a fourth adventure, this time summoned to the United States by his most famous acolyte. It seemed like his depiction of the pivotal figure in martial arts culture and Hong Kong history had come to an end with 2016's trilogy-capper Ip Man 3, but he returns for one last bout in a fitting conclusion that adds a global tinge to Ip's legacy. Many people think of martial arts and stunt work as a young person's game, so it may seem odd that it took Donnie Yen until his 40s to find his career-defining role as Ip Man, the father of 20th-century wing chun.