Tokyo is speculated in an alternative flood future where hard infrastructural strategies are no longer sought after, and the city instead adapts to its changing environment and relieves the ground plane from decades of concrete. A generative design methodology is employed with a genetic algorithm, inspired by Darwin's natural selection, as the city reconfigures itself and is rebuilt from the reclaimed building materials of the old city and instead hosts the new floating world, neo-Ukiyo. A metabolic process to rejuvenate the genetic and physical material of Toky