When Nobita asks Doraemon for the Moshimo-box, he unwittingly transforms the world into a realm of magic, leaving him struggling with spells unlike his peers. Desperate to reverse the enchantment, Nobita faces a setback when the Moshimo-box is disposed of. A chance encounter with Professor Mangetsu and his daughter, Miyoko, unveils a perilous threat from the 'star of the Underworld' nearing Earth. To save the planet, they embark on a mission to vanquish the Underworld King, guided by ancient prophecies. Despite initial failures and Miyoko's abduction, they use time-travel and teamwork to restore the Earth. Yet, the Underworld turmoil persists in a Parallel Universe, compelling the group to confront the tyrant ruler and free Miyoko once and for all.