Because of rising sea levels and a rapidly shrinking human population, androids have been engineered to handle most menial tasks, freeing humans to concentrate on other matters. In addition to providing manual labor and customer service, androids entertain humans through Babel—a tower where participants captivate audiences with song and dance to clear Climb Stages. The higher the climb, the more prize money is awarded. Androids Cobalt, Chrom, Neon, and Kei are down on their luck and face having their electricity cut off due to unpaid bills. Desperate to make a quick buck, the group decides to become Babel climbers. However, winning the audience's favor proves a great challenge. Dejected but unwilling to give up, Cobalt resolves to somehow improve their chances after watching an impressive performance by STAND-ALONE—the top climber unit. When the group stumbles across a mysterious choreographer willing to give away his routine, Cobalt sees this as their only way up. With the help of their human companion, Esora Shibaura, the androids form the unit KNoCC to tackle the daunting climb to the top of Babel, but they must also overcome android-based discrimination along the way.