Not since Disney’s Brother Bear (2003) has Joaquin Phoenix appeared in a movie so genuinely wholesome and light-hearted as Mike Mills’ C’mon, C’mon this holiday season.

A decade ago I never would have bet on the acclaimed, under-the-radar actor settling down as a family man, both on camera and off, given his bachelor days of art house flicks and Hollywood partying. But the change is proven, both with real-life fiancée Rooney Mara and their baby son, and on screen in Mills’ latest critical darling.

Following in the same vein as Mills’ previous hits, Beginners (2011) and 20th Century Women (2016), the director reminds us that he is at his best at finding the quaint and endearing in dysfunctional families.

Set in the present day, Johnny (Phoenix) is an audio producer traveling through every major city in the United States to record documentary comments from real-life teens on their thoughts of everyday life and how they see the future. Back home in Los Angeles, his younger sister Viv (Gaby Hoffmann) lives a hectic schedule of working; aiding her on-again/off-again lover Paul (Scoot McNairy), who is unpredictably manic and paranoid; and raising their eccentric 9-year-old son Jesse (Woody Norman).

The siblings are somewhat estranged since the long and slow death of their mother, Carol (Deborah Strang). To help ease Viv’s load, Johnny offers to watch over Jesse for three weeks while he works on the East Coast as she tries to convince Paul to get professional help.

Despite the R rating (which is only for two brief instances of foul language), C’mon, C’mon might be the best family film of 2021. Like Kenneth Branagh’s own family piece Belfast, Mills’ movie is shot in black-and-white, but has a more introspective quality.

Phoenix and Norman have a natural, candid chemistry that flows between them in scenes, and makes you feel like a fly on the wall. Norman successfully comes across as a legitimately precocious, yet adorable, kid; and Phoenix is his usual stellar self on film.

Though this is an uncle-nephew story, Hoffmann is given the most emotional beats, and makes me feel she would be a good Best Supporting Actress contender this season too. Along with some striking cinematography from Robbie Ryan, a lovely, retro soundtrack by Aaron and Bryce Dessner, and Phoenix and Hoffmann in some of the best sibling casting in recent memory, C’mon, C’mon is one to catch this month.