As the Japanese were remotely exploring the outer rims of the Moon to discover any signs of life, Nobita observed the cosmic sight from Earth and witnessed the lunar disc turn a shade of yellow. Emboldened by Doraemon's assistance, both voyagers journeyed to the Moon and fabricated bunnies that could construct their own settlement. Following their return, Nobita recounted their expedition to his classmates, but none took him seriously. However, the arrival of distant siblings, who seem to hail from an alien planet, altered their perspective.