孝之助（渡哲也 饰）在学生时代就开始爱慕着名为多江（吉永小百合 饰）的女子，一晃眼二十年过去，多江的一颦一笑依然深深的留存在孝之助的脑海之中。一场聚会中，孝之助意外的和多江重逢了，此时的多江经营着自己的花艺工作室，她的丈夫在早年间去世了。孝之助和多江的来往渐渐密切了起来，两人屡屡出游，倾诉他们深藏在心底的梦想。孝之助因为突发心脏病而住进了医院，前去探望的多江在医院捡到了孝之助的妻子佳子。这场会面让多江意识到自己正在做一件不可挽回的事情，于是决定离开孝之助，和自己的插花老师去京都学习。孝之助最终和佳子离了婚。

矢代个性超M又变态的人，从不会让别人看透他的内心。某天身边来了一名叫做百目鬼力的随从兼保镖。虽然早早就下定决心，绝不对不会对部下出手，但矢代不知为何，被百目鬼所深深吸引。彼此怀抱着自己的伤痛而活着的两人，他们的故事即将开始。

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。

Once upon a time, the birds and the beasts fought each other in a war. It was a terrible conflict, and the clever bats would side with the birds when the birds were looking victorious, and then they would become allies of the beasts when that side was winning battles. At last the war came to an end, the two parties reached an amicable settlement, and a great party of friendship was held. But when it came to the turn of the bats to perform in the program, their fence-straddling tactics were exposed, and everyone refused to associate with them. Since that time, the bats have been too ashamed to show their faces during the day, coming out only at night to flit silently around.