Sean Wang’s “Dìdi” (Focus Features, July 26) hits where it hurts for any millennial who came of age in middle school in 2008 — on MySpace and AOL Instant Messenger and in the throes of puberty. But it’s especially hard-hitting for Taiwanese-Americans raised in the California Bay Area at the time, as Fremont-hailing writer/director Wang’s big Sundance winner (including an Audience Award) is based on his own youth — one where he was often recalcitrant toward his single mom. In this frank and affecting dramedy, young actor Izaac Wang plays Chris, a 13-year-old spending the summer before his freshman year of high school surfing the web and making YouTube videos with his pals.

Until he falls in with an older crowd he seeks to impress. In the seemingly endless summer between eighth and ninth grade, there’s a crush, too, he’s trying to woo — with embarrassingly dismal results. Back at home, the second-generation Chinese schoolkid Chris bats away the affections and concerns of his immigrant mother Chungsing ( Joan Chen ), deals with a torturing older sister Vivian (Shirley Chen), and shares space with his helicoptering paternal grandma.

She’s played by Chang Li Hua, Wang’s actual grandmother, who makes her narrative debut here after featuring in Wang’s 2024 Oscar-nominated short documentary “Nai Nai & Wài Pó.” Meanwhile, Chen, best known to many audiences for playing Josie Packard in the original run of “Twin Peaks,” gives her most touchingly r.