There are a couple of eyewitness versions to this story, a little-known incident that took place in Japan during John Lennon’s years as a homebody. Clearly neither he nor Yoko were entirely housebound in those five years. They were out and about, just not making records at that point. I’ll try to present the version I like best. In all the nine years since he first conceived this song in Rishikesh, India, John had never played it live. And the one time he did, it was to an unwitting audience.
After winning his appeal to stay in the United States, John & Yoko visited Japan at least three times before his passing, beginning with a 1977 trip that lasted from May to October of that year. Yoko’s parents were upper class people who had a summer home in Karuizawa in Nagano Prefecture. During a stay at Tokyo’s Okura Hotel in 1977, while Yoko was visiting her family, John and his friend Elliot Mintz were lounging around in the presidential suite when an elderly couple evidently took the elevator to the wrong floor.
This couple has never been identified as anything other than an ‘elderly couple’. I’d love to know who they were, although at this point, only their relatives would know for sure. They wandered in and sat down, apparently thinking they were in a lounge bar. John found this entertaining and as Mintz related, he began to play “Jealous Guy” on his acoustic guitar.
The couple sat and listened for a few minutes before walking back to the elevator and going, which left John and Mintz in fits of laughter. “It was the only time I think he ever performed for a party of two,” Mintz wrote. “They did not leave a tip.”
https://www.nippon.com/en/japan-topics/g00979/
Karuizawa, Japan: In the Footsteps of John Lennon
Papablues Scrapbook 