Mario of the Deep
Mario, Luigi, Princess Toadstool and Toad have travelled to the underwater kingdom of Aqua Land in a submarine built from a bathtub in order to fight against Barra-Koopa. Shortly after the group's arrival, Toad points out to a female Mermushroom being chased by a Bloober octopus, who is carrying a trident. Mario opts to stop the Bloober, and drives after him in the submarine. As the Bloober succeeds in grabbing the Mermushroom, it comes to a halt, just after the submarine parks itself next to him.
Wielding a plunger, Mario leaps out of the submarine and demands for the Bloober to leave the Mermushroom alone. The Bloober tosses the Mermushroom aside, and prepares to duel Mario with his trident. As the Bloober attempts to stab Mario, he leaps out of the way, leaving Luigi to ward off the attack with his own plunger. Mario lands behind the Bloober but fails to sneak up on him. Luigi tries to smack the Bloober with his plunger, but he shields it with his trident, and sends Luigi flying over to a boulder. Reclaiming his stuck plunger, Luigi pulls it off of the boulder with too much force and goes flying, hitting the Bloober right in the face with his plunger as he lands. Afterwards, Luigi gets his head stuck in a sea anenome, imparing his vision.
A moment later, the Bloober cracks the sea anemone off of Luigi's head, and attacks him with his trident. Luigi barely dodges the Bloober's stabbing, and attempts to intercept him with his plunger. Realizing the danger that Luigi is in, Mario spots an anchor lying on the seabed. Twirling the anchor's chain like a lasso, Mario tosses it at the Bloober and knocks him unconscious.
As Toad thanks Mario and Luigi for defeating the Bloober, the Mermushroom comes out of hiding and gives them her thanks as well. Princess Toadstool questions the Mermushroom as to why the Bloober was chasing her, and she explains that he is working for Barra-Koopa, who is kidnapping all the citizens of Aqua Land and turning them into slaves. Princess Toadstool asks where Neptune, Lord of the Deep is, and the Mermushroom tells her that he has been imprisoned by Barra-Koopa. The Mermushroom then pleads for the group to help her people and free King Neptune. Mario then tells her that it is the reason they came.
Meanwhile, in the throne room of King Neptune's temple, Barra-Koopa is sitting on the throne before King Neptune, with a Bloober by his side. Barra-Koopa mocks King Neptune, laughing at the fact that he is now his prisoner, and can proceed with taking over Aqua Land. King Neptune tells Barra-Koopa to mellow out, but Barra-Koopa does not understand his reasoning, and orders the Bloober to send him to the dungeon. Barra-Koopa then laments on the fact that he cannot stand a nice king. At that moment, the Bloober that had fought with Mario and Luigi, now covered in bandages, enters the throne room and alerts Barra-Koopa about their arrival in Aqua Land. Barra-Koopa declares that Mario and Luigi are never going to spoil his fun again, and orders for the Bloober to sound the Koopa Pack attack.
Soon, an alarm goes off, and Trouters are out on patrol throughout Aqua Land. The Mermushroom then points out to Mario's group that Bloobers are forcing the citizens of Aqua Land to gather up the Gold Coins from inside the kingdom's sunken ships. Princess Toadstool insists that they must help the Mermushrooms, and Mario comes up with an idea, which he whispers to the others. Luigi objects to Mario's idea, and Mario, taking offense, asks him if he is a man or a Mouser. Luigi says that he is neither; instead, he calls himself a chicken of the sea, but agrees to go along with Mario's plan anyway.
Soon afterwards, a piece of a ship mast lands on top of a Bloober guard and knocks him out, courtesy of Mario. Luigi then pokes his head out of a hatch near another Bloober, gets his attention, and allows himself to get chased back into the hatch. The Bloober is unable to locate Luigi, who surprises him by sticking a life preserver around his tentacles. Luigi then pulls the plug on the life preserver, which sends the Bloober flying out of the ship. Princess Toadstool puts on a cheap-looking Bloober costume, and approaches three Bloober guards, whom she offers kisses to. The Bloobers' eyes light up in delight, and while they are distracted, Toad drops on oar on all three of them simultaneously, knocking them out.
Toad and Princess Toadstool then meet up with Mario and Luigi again, and the Mermushroom praises them some more. Mario points out at the rate they are going, they will free the Mermushrooms in no time. All of a sudden, Barra-Koopa shows up and counters Mario's comment. He then orders some more Bloobers to toss nets at Mario's group, which they all get trapped in. Barra-Koopa tells them that he is going to flush them down the drainpipe of doom, and laughs.
Later, Barra-Koopa has Mario's group thrown into a hallway in one of the sunken ships. Mario demands to be released, but of course, Barra-Koopa does not comply. Instead, he laughs, tells the Bloobers to come with him as he proceeds to plunder Aqua Land, and seals Mario's group in behind the door. The Mermushroom points out that they are trapped behind the door, and Toad wonders what Barra-Koopa has in store for them at this point. Mario says that he does not know, but he suspects something fishy. Just after Mario makes his remark, Luigi points to a school of Trouters swimming in their direction. The five of them flee from the Trouters, but as they turn the corner, they encounter a patch of potted Piranha Plants. The group manages to either leap or swim over the Piranha Plants, and head towards another door. Passing through the door, Mario manages to close it just before the Trouters reach them.
Princess Toadstool remarks that they are now safe, but their victory is short-lived, as a Clawgrip starts to approach them. Luigi fears that they are doomed, but Mario points out that there is a hatch they can escape through if they can get past the Clawgrip. As the Clawgrip chases after the group, they all leap over it, and duck down into the hatch, which is too narrow for the Clawgrip to fit through. The hatch leads the group out through the bottom of the ship, but Princess Toadstool reminds the others that they still need to save King Neptune, as he might be able to help them defeat Barra-Koopa. Toad, however, points out that they do not know where King Neptune is being held. The Mermushroom speaks out, informing the group that she knows a secret passage leading into Aqua Land's dungeon, and prepares to lead them to it.
Inside the dungeon, King Neptune mopes about being capture, and comments that he needs to get out. Suddenly, a large brick in one of the walls is pushed inwards, and falls down to the floor, revealing an passage that Mario enters through. Startled by Mario's entrance, he is then introduced to the plumber, along with the rest of his friends as they enter the dungeon. The Mermushroom explains to King Neptune that Mario's group has come to rescue him and to help fight Barra-Koopa. King Neptune suggests that they simply launch an attack on Barra-Koopa, but Princess Toadstool explains that they would be outnumbered. King Neptune assures her not to worry, because he is going to round up some of his fishy friends for their assistance.
Back in the throne room, a Bloober presents Barra-Koopa with Treasure Chests containing the last of the coins from the sunken ships. Displeased with the total amount of plundered coins, Barra-Koopa expresses his anger, but is soon interrupted when the whole room starts to shake, and questions as to what caused it.
Outside the throne room, a large whale, which King Neptune is riding atop of, is slamming against the building. Soon, one of the walls cracks open, which Mario, Luigi, Princess Toadstool and Toad all enter through, each riding atop a seahorse and wielding a swordfish. Angered by their entrance, Barra-Koopa orders a trio of Bloobers to attack them. Mario confronts Barra-Koopa by himself, and proceeds to battle him with his swordfish, while Barra-Koopa uses his trident. Fighting one of the Bloobers, Princess Toadstool succeeds in cutting his trident with her swordfish, then kicks him in the face. Toad manages to slice through the trident of his Bloober, and headbutts him. Luigi then knocks the trident away from his Bloober, and punches him in the face.
Still fighting against Barra-Koopa, Mario continues to dodge his attacks, and succeeds in cutting through his trident with his swordfish. Mario then tosses his swordfish at Barra-Koopa, and it chases him out of the throne room, stabbing his backside repeatedly, even as he runs down the stairs leading to the temple. Everyone laughs at Barra-Koopa's defeat, and King Neptune thanks the land-dwellers for their help. Mario comments that their fish tale came to a happy end, but Luigi points out that it did not for Barra-Koopa, who continues to run through Aqua Land with the swordfish still in hot pursuit.
Animation and continuity errors
Names in other languages