“Tokyo” is a song developed by U2 as they were working on Rattle and Hum.
In 2017 Daniel Lanois talked about this track in an interview, about how he was involved in one track on Rattle and Hum:
“I was only involved in one track on that record, which was originally called, “Tokyo,” but I don’t know what it’s title is on Rattle and Hum. I was not very close to that record, although there were some great things like the remake of “I Still Haven’t Found What I’m Looking For.” When I spoke to the band when they were going to do this project, their spirit was something more disposable, more of a fun thing, not so serious, connected to the tour. But it’s not disposable. It has become a success with the audience”.
The song “Heartland” credits lists, “Recorded by Kevin Killen and Daniel Lanois at Danesmoate, Dublin. Assisted by Pat McCarthy.” This was a left over from the recording sessions for The Joshua Tree which was recorded at Danesmoate. Thus “Tokyo” is probably an earlier working title for the track.