Other than one brief scene in color it is entirely in black and white. Early on it put me in mind of Cory McAbee's wonderful space-western/musical THE AMERICAN ASTRONAUT (2001) in that it shares the same approach with a simplistic unconventional design to the spaceship and the way it is seen in the exterior shots as it travels through the lonely cosmos. With THE WHISPERING STAR the interior design has old timey retro gadgetry and commonplace items like a washing machine and a refrigerator full of what looked like cans of beer. In both films these scenes were intentionally styled as oddities and both were effective despite being low budget. But that's where the similarity in the films ends as they become quite different experiences.
There is very little dialogue in THE WHISPERING STARS, and it's all done in whispers, lending meaning to the title. The onboard computer is called "computing device 6-7 MAH Em" and it talks in the quiet voice of a young child, trying to engage android Yoko Suzuki, a courier in the "SPACE PARCEL SERVICE," in conversations, which are largely ignored by the latter. Even seemingly important decisions on coarse corrections go unresponded to so 6-7 MAH Em just deals with whatever needs to be done while Yoko is more likely to grab a beer from the fridge, study the pile of packages yet to be delivered, or listen to old voice recordings she made. Days pass, even years, with nothing much happening in between the brief stops on planets to deliver packages to humans, all of which has us (and Yoko) wondering at the meaning of the contents of the packages which often seem trivial or unexplainable mysteries at best.
Interesting too is that the scenes taking place on the planets were filmed in and around the mostly abandoned city of Fukushima, Japan, where the nuclear power plant catastrophe occurred. Which enhances the feeling of questioning loneliness that Yoko feels as she goes about her deliveries.
Very different sort of film for Sono but I liked it and, if anything, I am more impressed by him than ever. There is no telling what he will come up with next but I'll be along for the ride.