First off, I love Hibito's Corvette Stingray in the OP. Corvette became the
unofficial car of the Mercury astronauts. The Stingray is from the late 1960s; the photograph at the top of the linked article is from 1969. Hibito's 'Vette has a "two-tone" paint job, too. I liked the brief shot of the 1950-ish Ford parked next to a fence. Is that to show Japanese people the American car culture? These scenes almost seem a tribute to cars in America.
Then there was the hoe-down scene. I find it a bit hard to believe that this scene is based on participant observation of actual NASA parties, but you never know. And Hibito had taught himself all the songs! Whatta guy!
Wasn't there a bit of jealousy in Mutta's voice in the promo when he hears that Serika is buying a Hibito poster? The subject of Hibito has come up before with Serika seeming to have a little crush on younger brother. It drove Mutta crazy then as I recall. I don't think Serika and Hibito have met, have they? It's a good thing Hibito is leaving, or Serika would probably ask Mutta to introduce her!