A group of terrorists has taken hold of the largest dam in Japan. They also capture the workers as hostages, and demanded $5 billion yen from the government with a 24 hour deadline in exchange for the lives of the hostages. To make things more complicated, there was a snowstorm and no one can get in or out near the area. Fortunately, the terrorists did not capture Togashi, the dam controller, and he is the only person who can rescue those hostages from the terrorists...

小夫的炫耀一如既往让大雄气愤不已，为了帮大雄实现潜水的心愿，哆啦A梦将整个城市变成了虚拟海洋，并利用道具引来了海洋中的生物。一个美人鱼来到了城市里，却阴差阳错被困了下来。她名叫苏菲亚，是人鱼一族的公主。据说，人鱼族在五千年前生活在另一颗星球，爱好和平的他们因受到另一族的侵略而来至地球避难，从此在这里扎根。大雄、静香他们很快和苏菲亚成为好朋友，并答应帮她寻找人鱼族传说的宝物“人鱼之剑”。正当小伙伴们在深海中尽情玩耍之时，危险不期而至。当初侵略了人鱼族家乡的外星恶魔也来到地球寻找人鱼之剑，小伙伴们即将展开新的冒险……
本片为哆啦A梦剧场版开播30周年纪念作品。

Nobita finds a passage to a spaceship in another dimension. With their new friends, he and Doraemon fight the cruel leader of an exploited planet.

A man arrives in the city upon news of a potential terrorist strike in Italy. He is Japanese foreign diplomat, Kosaku Kuroda, and he’s here under orders of his supervisor at the Foreign Ministry, Hiroshi Kataoka (Kiichi Nakai), to aid in the safeguarding of Japanese citizens. Kuroda’s main contacts at the Japanese embassy consist of Ambassador Kikuhara, Counselor Nishino, and fellow diplomatic envoys Haba and Tanimoto. All are busy preparing for the visit of Japanese Foreign Minister Kawagoe due to arrive for the high-profile G8 foreign minister’s meeting. Meanwhile, somewhere on the festively-lit streets of the city, a young Japanese girl has suddenly gone missing. Is it an abduction simply for ransom? Or could it be a prelude to terror?

A fugitive alchemist with mysterious abilities leads the Elric brothers to a distant valley of slums inhabited by the Milos, a proud people struggling against bureaucratic exploitation. Ed and Al quickly find themselves in the middle of a rising rebellion, as the exiled Milos lash out against their oppressors. At the heart of the conflict is Julia, a young alchemist befriended by Alphonse. She'll stop at nothing to restore the Milos to their former glory – even if that means harnessing the awful power of the mythical Philosopher's Stone.

大雄最近有点儿倒霉，在学校因为功课被老师训斥，打棒球技术差被伙伴们嘲笑，房间太乱遭到妈妈责骂。伤心的他异想天开，希望有某种魔法能帮他搞定这一切。在哆啦A梦的“假如电话亭”的帮助下，他们的世界变成了一个魔法的世界，不幸的是大雄依然是最差的那个。
与此同时，神秘天体正在接近 地球，魔界之王戴玛奥企图统治世界，他预测到大雄和他的朋友们将是他前进道路上的阻碍，于是他派出魔女美杜沙铲除这些绊脚石。大雄他们遇到了空前的危机……