it was Megazone 23
Hey, a few years back me and my sister saw some anime from the 80s or 90s. It’s either a film or an OVA, probably two parter if it’s a film. The basic story was that earth is shattered and many cities are now space stations (such as tokyo) however the people living in these cities are not aware of this and think they are still on earth. There was also some strange underground “city”. Also, there was a computer pop star. There were some motorcycle scenes too. It’s not Akira.