But 1983? Official records show Nobita’s Underwater Adventure does exist. The 1983 slot was occupied by a medium-length film released alongside a Perman spin-off. That film was Nobita’s Monstrous Underwater Castle (海底鬼岩城, Kaitei Kiganjō ).
The story begins with a heatwave hitting Tokyo. Nobita, frustrated with summer homework and a broken air conditioner, begs Doraemon to take him somewhere cold. Instead of the Antarctic (already covered in another special), Doraemon pulls out the "Deep-Sea Hiking Set" and the "Undersea Tent." The gang—Nobita, Shizuka, Gian (Jaiko), and Suneo—descends into the Japan Trench. Doraemon Underwater Adventure -1983- REMASTERED...
Doraemon the Movie: Nobita and the New Castle of the Undersea Devil . Scheduled for release on February 27, 2026 , it serves as the 45th film in the franchise. Crunchyroll Plot Summary But 1983
At its core, "Doraemon Underwater Adventure" is a story about exploration, friendship, and the power of imagination. Nobita and Doraemon's journey represents the human desire to explore the unknown, to push boundaries, and to discover new wonders. The episode also highlights the importance of teamwork, as Nobita and Doraemon work together to overcome challenges and achieve their goals. Instead of the Antarctic (already covered in another
Doraemon: Nobita and the Castle of the Undersea Devil (1983) - IMDb
: The film launched across 387 theaters in Japan, marking a significant theatrical event for the franchise.