Brendan Fraser is a bland and ingratiating presence in this glib, silly and pointless film from Japanese actor turned director Hikari. It is bafflingly complacent in its sentimentality and its sheer, fatuous implausibility, which makes it valueless and meaningless as drama and comedy.

Fraser plays Phillip, a hapless unemployed actor from the US who a few years previously came to Tokyo to do a goofy TV ad for toothpaste and, having no friends or family back home, simply stayed on. He lucks into a weird new source of income: working for a “rental family”, based on firms in Japan which really do offer bespoke therapeutic role-play services, such as errant spouses, deceased loved ones or unsatisfactory co-workers – people who can be chatted with, or mourned, or yelled at for cathartic purposes.

Phillip, who has issues of his own with a father who ran out on his family when he was a kid, finds himself having to be a dad to a little girl whose single mother needs a respectable father figure for an elite private school interview; the kid is told this is the guy who disappeared when she was a baby. And he is also to be effectively a mock son to an ageing actor, whose grownup daughter fears he is depressed; she hires Phillip as a phoney interviewer tasked with writing a flattering in-depth profile.

In fact, Werner Herzog has already made a film on this subject, Family Romance, LLC from 2019, in which Herzog exerted himself to acknowledge, just a little, how bizarre, dysfunctional and fundamentally irresponsible the whole business is and how likely it is to make matters worse once the imposture is discovered. Yorgos Lanthimos’s surreal satire Alps addressed a similar theme. I found both these films uncertain, perhaps because there is something uncomfortable about adding a layer of role play to the existing play-acting of fictional films.

But this one has a serious tonal problem, wanting to turn it all into feelgood slush with some vacuous platitudes about how we are all playing roles. (Not like this we aren’t.) Phillip has to impersonate a mock groom on a phoney wedding day for a young woman who wants to hide a certain truth from her parents, and there’s supposed comedy in the twist-reveal. It’s a reactionary patriarchal society, sure, but should this woman be lying to her old mum and dad like this? And if lying is the only way forward then shouldn’t the tone be something other than quirky farce?

Then there’s the little girl whose heart he is apparently willing to risk breaking by pretending to her that he is her real dad. He is finally shown explaining and apologising to her – but not to the poor older actor. There is something fundamentally wrong-headed about this smug, saccharine film.

• Rental Family is in Australian cinemas now, and in UK and Irish cinemas from 16 January.