- Goombella (the Goomba from Paper Mario: The Thousand Year Door)
- An unnamed Yellow Toad
- Yosher (a Yoshi)
- Booker (a Boo)
- Wanda (a Magikoopa)
- Koko (a Noki)
- Bloopa (a Blooper)
- Starlight (a Luma)
- Paul Pianta (a Pianta)
- Vivian (the Shadow Siren from Paper Mario: The Thousand Year Door)
Prologue: The Summetime Festival
It was a summery day in the Mushroom Kingdom. Mario and his brother, Luigi, were tidying up around the house, when there was a knock at the door. It was Mailtoad, and he had a letter from Princess Peach. It said:
Dear Mario and Luigi,'The Summertime Festival is taking place at the castle. I do hope you can join us.'Yours truly, Peach
Mario and Luigi almost forgot about the Summetime Festival. So they got ready and set off to Peach's Castle.
Along the way, the brothers (literaly) ran into an old friend of theirs, Goombella. She seemed very paniced. She told Mario and Luigi that she was having a good time at the Summetime Festival, when suddenly Bowser crashed the party, along with eight Bowser-like creatures that were smaller than him. The brothers were shocked at this, and they began to make they're way with Goombella.
At the castle, Bowser, Bowser Jr., and the Koopalings were at the festival. Mario, Luigi, and Goombella arrived to stop them in just enough time. After battling Bowser, he says that his master plan is too far ahead for them to stop. And with that, Kammy Koopa appeared and trapped Peach in a magic dome, and Bowser and his sons and daughter left on an airship. Mario, Luigi, and Goombella then started to go after them.
Chapter 1: Larry's Goomba Grotto
Mario, Luigi, and Goombella had just begun they're journey, when they noticed what looked like a harmed person. The harmed person was a Yellow Toad. He said that the Goomboss attacked him just for getting lost in Goomba Grotto, since only Goombas are allowed there. Goombella admits Goomba Grotto is her home town, and if anyone knew her way around there, it would be her. The Toad also said that there was one that didn't look like a Goomba, yet he somehow had a power over them. Goombella thought Goomboss had become good, and that all the Goombas in Goomba Grotto were good. She was confused.
Later, at Goomboss' Castle, Larry Koopa leaped infront of the team. The Toad recongized him as the one who was controlling the Goombas. Larry had a device that could hypnotize a Goomba. The device was built by his two inventor brothers. After beating Larry, he calls in for Goomboss and sends him to fight him. After defeating Goomboss, he snaps out of it, and so do all the Goombas of Goomba Grotto. Goomboss then punishes Larry by dangling him from a rope over a lake with a Sharkoomba. He thanked Mario, Luigi, Goombella, and the Toad for saving Goomba Grotto, and even told them where Bowser was headed next.
Chapter 2: Delfino Delemma
At Delfino Plaza beach, Iggy was relaxing on the beach, not noticing his father's face on a monitor next to him. Iggy soon noticed and tried to explain, but Bowser just said to find a way to destroy Mario.
Mario, Luigi, Goombella, and Yellow Toad have arrived at the town, where they met a Jamacan-accented Pianta named Paul Pianta. He asked the gang if he can help them. Mario explains that Bowser had kidnapped the princess. Paul didn't like the sound of that, so he joined the team.
Later, after making it to Rico Harbor, Mario and Luigi felt a rumbling. Paul looked and saw the sea was murky with ink. Suddenly, Iggy came out and prepared to fight. After beating him, Iggy summons Gooper Blooper to fight them. After defeating the large Blooper, Iggy found himself surrounded by angry Piantas and Nokis. One of the Nokis was a huge fan of Mario, and her name was Koko. Koko begged Mario to let her join. Paul asked Mario if they should, and Mario said "okie-dokie".
Chapter 3: Shipwrecked on Chomp Island
As it turned out, Koko's dad is the owner of a ship rental shack. After getting themselves a ship, they meet they're crew, which is a bunch of Shy Guys, Bob-omb Buddies, and one Big Bully. Soon after leaving the docks, Mario and the crew encounter a Blooper named Bloopa. He challenged them to a fight. After beating Bloopa, his brother, Bloopario, came up and told them to stop fighting, saying that Bloopa was only following Wendy's orders. Mario told them that Wendy is a Koopaling, and that they are children of Bowser. Bloopa, now realizing he's been tricked, got very angry. He joined Mario and the crew to get back at him. But suddenly, the boat began to rock, and they all found it being attacked by Cheep Chomps and eel-like creatures. The ship began to sink, as the creatures continued to attack.
Later, on a place called Chomp Island, Mario and the crew find themselves shipwrecked. Koko seemed paniced at first, until a Bob-omb Buddy calmed her down. Mario agreed to go find help on the island.
After treking through the jungle, Mario and Koko found a village, where Chief Chomp and other Chomp natives attacked them. After defeating the chomp natives, Mario and Koko found out that they though Wendy was a godess. Wendy got on a platform attached to Chief Chomp's chain, and a battle begins. After defeating Chief Chomp and Wendy, the Chomps realize they have been tricked and chase Wendy all over the island. The Big Bully came to Mario, saying that they fixed the ship.
Mario and the crew sailed off into the sunset.
Chapter 4: Magikoopa Isle
The ship has docked, and the Mario brothers came off, Luigi being more frightened. They heard Peach's cry, and they saw her at the top of a tower. On they're way to the tower, they meet a Magikoopa named Wanda. She says she is still practicing magic with her mother, and she is actually a good Magikoopa. She joins them, agreeing to help them save Peach.
After time of adventuring and enemy-fighting, they get to the top of the tower, where Peach is locked in a cage. Wanda is about to free her with her magic, when suddenly, a somewhat British voice is heard, and Ludwig hops down with Kammy. Wanda admits that Kammy is her mother, and tries to save her before she realizes her mother works for Bowser, who was who took Peach in the first place. Wanda felt crushed. After fighting Ludwig and Kammy, Wanda uses her magic to trap them is a magic bubble and send them bouncing off, and floating into the ocean. Kammy tried to break it with her magic, but she couldn't due to a spell lock. Peach thanks Mario and Wanda for freeing her. She tells them that Bowser is still ahead, but he can still be stopped.
After this, Peach becomes playable.
Chapter 5: Yoshi Island
After much adventuring, the gang ran into Morton. He had two Dry Bones with him. After beating him, the gang gets out, and just in time, for the tower was due for demolition! Morton was sent flying off, vanishing into the sky.