20,000,000 People (2000万人, 2000 Man-ri) is the 9th chapter of Clockwork Planet manga series.
As the purge is about to commence, Marie formulates a plan to save the city. She postulates that the usage of gravity to descend the city can be reversed into anti-gravity using RyuZU's Imaginary Gear for 30 minutes while the Meister Guild reverses the purge. Naoto refuses to hand over RyuZU, but she rejects his order and sacrifices herself to give Marie her Imaginary Gear. Just as the military initiates the purge, they are shocked to see the city fly upwards and send in reinforcements to apprehend Marie. Naoto and Marie work together to detect and destroy the incoming military helicopters by manipulating gravity. After she finishes using the Imaginary Gear, Marie quickly repairs RyuZU, and she and Naoto rejoice at each other's company.