Mario and Mallow left Mushroom Kingdom and went down the warp pipe to Kero Sewers. Walking and swimming through the maze of underground waterworks, the duo confronted fish-like Gero and ghost-like Boos. Mallow's normally weak physical attacks proved more effective against the ghosts. After finding a switch that drained the water, they were able to pass through the sewers but found their way blocked by a monster called Belome. "It's a snack attack! And you're it!" he said. During battle, Belome succumbed to temptation and swallowed Mallow whole, but after a few whacks from Mario's hammer spat Mallow back out. "Beware the flood!" Belome warned just as he was defeated, and to their surprise a sluice gate raised and a violent wall of water washed Mario and Mallow away.
Our heroes were safe, though, and were washed down the nearby Midas River falls. Fighting against the downward current, Mario picked up a few regular coins and Frog Coins on the way down, and at the bottom they found himself on the Midas River barrel run. Running in place on the spinning barrels and hopping to avoid collisions, he made it to the end of the course and found a mushroom-person in charge of exchanging the Midas River currency for real money, and offering a ride back to the top to try again. They had no time to try the ride again, though, so they left, but not before Mario recieved a first-timer consolation prize, the NokNok Shell, a new weapon for Mario!
Mario and Mallow continued to Tadpole Pond, where Mario obliginly showed off his legendary jumping skills to the tadpoles, and Mallow's grandpa, Frogfucious, invited them to convene with him. The waterways that pass through Tadpole Pond bring news from all around the world, so he related to Mario the truth that Princess Toadstool and Bowser were also scattered from the impact of the sword and lost somewhere in the world. "Smithy's Gang" of minions, of whom "Mack" was a member, were wreaking havok on the world and Frogfucious implored Mario that he would need to take care of Smithy in the course of rescuing the princess. It was rumored that stars can grant wishes, so Frogfucious suggested that the star they had found would be instrumental in restoring the world. He revealed to a surprised Mallow that he was not actually a tadpole! Frogfucious found Mallow as a young baby floating in a basket and adopted him. He and assigned Mallow to assist Mario on his quest with his powerful magic spells and journey with him to find his real parents. He told Mario the next place to go would be Rose Town, where his help was needed, and in exchange for the Cricket Pie they brought back gave Mallow his old "Froggie Stick", a travelling weapon for Mallow.
The renewed duo travelled down Rose Way to get to their destination. Rose Way was a jungle area with small lakes and floating platforms that they used to get around. Just before reaching the exit, Mario and Mallow spied Bowser rallying a small unit of koopa troops, intent on finding another way back into his castle to retake it. They waited for the force to leave before continuing through, reaching Rose Town at nightfall. The stripey-headed mushroom-person inhabitants of Rose Town were under seige from pertrifying arrows that had started raining from the nearby forest after a star fell from the sky.
Entering the town inn, they met Gaz, a young boy playing with dolls of Mario, Princess Toadstool, and Bowser. After the Bowser-doll clobbered the Mario-doll (much to the dismay of Mario himself), Gaz excitedly recognized the famous guest and called his mother over. Offering to play with Gaz, Mario had to play the role of Bowser. "...since Mario kicked the bucket," said Gaz. He then got out a mysterious doll named Geno, activated the dangerous-sounding patented projectile action feature, and accidentally knocked Mario out cold. Whilst Mario slept in a bed Gaz's mother had helpfully tucked the unconscious Mario in, a tiny sparkle of light came upon Gaz's dolls and descended on the Geno-doll, transforming it into a life-size Geno that wandered away.
Mario awoke and went downstairs to find Gaz yammering on about how Geno had come to life in the middle of the night and wandered into the forest. Curious about the goings-on in that forest, Mario and Mallow went there to see what was up. The Forest Maze was full of bees, caterpillars, and hollow tree stumps leading underground. They caught up with the now-life-size Geno doll and tailed him until they came upon a strange creature, Bowyer, who looked like a bow and talked like Yoda, and was surrounded by henchmen that looked like arrows. One of the henchmen approached dragging a green star it said it had found nearby. Remaining out of sight, Mario and Mallow hid further when they saw Geno approach Bowyer and implore that he return the star where it belonged. Quick to anger, Bowyer started hailing arrows randomly all over the forest. "Chill out!" Geno begged.
Mario and Mallow decided to help Geno and confront Bowyer. "I will do what I can!" said Mallow, but as they sprinted to the aid of Geno, Mallow fell victim to one of the raining arrows. He managed to catch up just in time to fight with the mad Bowyer. Between Mario's might, Mallow's magic spells, and Geno's powerful action feature, the three managed to dispatch Bowyer. After the fight, Geno introduced himself as a being from "Star Road" where the world's wishes are all granted. He travelled from Star Road and inhabited the body of the strongest-looking doll in order to collect all of the missing stars that had been broken from Star Road when the giant sword descended from the sky. "The way things stand, your's is a world where wishes can't come true anymore," he warned.
Geno asked for Mario's help to find all 7 stars and get rid of Smithy so Star Road could be repaired. As Mario grabbed the green star, one of Bowyer's henchmen, who had heard everything, ran off to tell Smithy the news about the Stars. The trio of heroes returned to Rose Town and found the inhabitants grateful that they were rid of the rain of arrows. Geno and the rest tried to explain to Gaz what had happened via an elaborate pantomime, but Gaz didn't get it. When Geno simply told him that none of his wishes could come true, Gaz implored Geno to help Mario on the quest "because Mario's going to need all the help he can get!" Mario was getting quite fed up with the recent slander against his prowess, but Gaz's mother offered them to stay at her inn for free. After a nap, Mario felt like a new man, and the heroes prepared to set off and continue their important mission.