I found some slides at a 2nd hand store here in Tennessee and I will say Japan 1960's. Here is a link to the album so far I have scanned about 30 of them all Kodachrome in 35mm and 126 format.
Family trip, one older couple and a younger one with 4 children? (the younger husband is missing in these pictures, which often happens with designated photographers).
One car looks like a Toyota Corona T40(T50, those were produced from 1964 to 1970. Ladies' hairstyle is another possible indication of date, mid-1960s.
That was no ordinary Instamatic camera they were using. I'd guess it was one of the better ones, like the Kodak Reflex Instamatic, the 500, or the like. Great pictures, Larry. There's a family somewhere that wonders where they went.