Apparently a lot of custom built hard/software some using MAX for live. He has his own developer/collaborator called Nibo. This is how he describes working with RS.
“One example of this is a live analysing tool that Nibo and I built. It also functions as a sine wave generator. Its purpose is to analyse what Ryuichi plays, in this case, and then it gives me a precise frequency of the decay of the tone. I then have a choice on which sine waves I am going to add, lower or higher. I can do this in my studio, in an offline situation, but it’s not possible to do it live on stage.”