Well, perhaps things were a bit easier...and rarer...for that tarento from overseas. I didn't get to see her nearly as often as I did the above mentioned fellows, but there was an Italian lady by the name of Rosanna Zambon who was a longtime resident in Japan who used to pop up as a talking head on one of those shows or as a guest cook to whip up some dishes from her home country (and boy, do the Japanese LOVE their pasta).
I also realized that a long time ago she was one-half of a duo known as Hide & Rosanna（ヒデとロザンナ）who often popped up via vintage footage on those kayo kyoku retrospectives. For this article, I'm profiling their debut single from October 1968 "Ai no Kiseki" (The Miracle of Love). Hide was born Hideo Kato（加藤秀男）in 1942 in Tokyo and debuted as an actor under the stage name of Eiji Mizuki （水木英二）before making his start as a singer in 1962 with "Tokyo Romantic Guy". Changing that stage name once more to Hide Demon（出門ヒデ）, he made another start of it in a duo known as Yuki & Hide（ユキとヒデ）in 1966 before that fizzled out a couple of years later. Then, in that same year, he met 18-year-old Rosanna who had arrived in Japan a year earlier at the encouragement of her uncle who was performing as a musician there. After that, "Ai no Kiseki" made its debut.
I'm sure the suits at Nippon Columbia were wondering if a miracle indeed had happened with this song and this duo. Written by Kotaro Nakamura（中村小太郎）and composed by Shinichi Tanabe（田辺信一）, "Ai no Kiseki" became a huge hit for Hide & Rosanna. Starting out with some ominous strings, the song goes immediately into that snare drum-and-horns arrangement that automatically yells natsumero for me ("Blue Light Yokohama" has the same effect). My only problem with the song is just that cornball instrumental section when Rosanna starts wailing plaintively in Italian, but my impression is that having a foreign language incorporated into a kayo must have given the tune that extra oomph of character according to the songwriters.
But I digress. As I said, "Ai no Kiseki" got Hide & Rosanna on the map. It peaked at No. 6 on Oricon (it kept hovering in the Top 10 for almost 2 months) and was the No. 25 single of the year for 1969.