Marche and his sick brother, Doned, moved into St. Ivalice following their mother who believed a change in environment would be good for Doned's health. The Radiuju family had lived in a hot place where it never snowed.

At school, Marche receives the nickname "New Kid" by the bullies Lyle, Colin, and Guinness, and is teased at for being quiet like "a little girl", but he ignores them. He befriends Mewt Randell, and Ritz Malheur, the Class Head.

After school, Marche and his new friends meet at his house to look at Mewt's new book on monsters and magic. On their way to Marche's house, Marche explains about Doned, his little brother, who always visits the hospital for his unknown illness.

The town of St. Ivalice.

They encounter Mewt Randell's father, Cid, who greets Mewt and asks if he had a nice day. Ritz comments they rarely find a father acting like that. In the Japanese version, Cid appears drunk, while in the English version some citizens are charging him money. Mewt explains that after his mother died his family went into financial trouble. After the conversation between Mewt and Cid, they continue on to Marche's house which is "the house with the yellow roof".

As Marche arrives at the house he encounters Doned, who sits in a wheelchair. Doned inquires how Marche is doing and after Marche answers he had a snowball fight, Doned teases him that he cannot play sports well.

The Gran Grimoire.

Ritz and Mewt come to Marche's house and introduce themselves. Mewt opens the old book, which has the illustration of the bangaa, viera, nu mou, human, and moogle. Ritz states the language written on the book looks like Latin, and Mewt reads Alta Oron Sondus Kameela. The kids think it would be great if a game world like "Final Fantasy" becomes the real world. As the kids sleep St. Ivalice transforms into a dream Ivalice; the snowy landscape changes into a hot climate filled with fantasy creatures.

The Gran Grimoire.

When Marche wakes up he finds himself stranded in a strange land. Unintentionally offending a bangaa, he receives Montblanc's help who becomes his guide in the country called Ivalice, and joins Montblanc's clan, Clan Nutsy. Marche makes it his mission to return the world to normal and to find his friends.

While on the mission "Twisted Flow", Marche is transported into a strange dimension with a crystal. Before he can approach it, a being known as Famfrit appears, proclaiming himself a Totema, a defender of the crystal. Marche engages the Totema in battle and is victorious. After Famfrit joins Marche's cause, the crystal shatters and an image of Mewt in pain appears. A voice tells Marche that what he destroyed was one of the world threads, and that if all are destroyed, a new world would be born. Taking this as a hint on how to get his world back, Marche resolves to destroy the world threads.

Marche's next mission introduces him to the famous Ezel Berbier, who is under attack from several warriors aligned with the judges. After helping Ezel, Marche is shown first hand the power of the Anti-Law cards. From then on, Ezel considers Marche a close friend and valuable customer.

Marche Radiuju, the protagonist holding a judge sword.

In the mission "Hot Awakening" Marche finds the next world thread. While at Roda Volcano, an earthquake opens up the portal to the crystal. He is confronted by the next Totema, or at least one of its forms, the Ultima Crystals. Upon defeating Ultima and shattering the crystal, another image of Mewt appears, this time demanding to know who is trying to destroy his dream world. When Marche returns to Ivalice, he has second thoughts about going about destroying his friend's world.

During the mission "Pale Company" Marche is ordered to find a ghost. Entering the Nargai Cave, Marche finds a spirit, and follows it into a portal and into a crystal chamber. The ghost is here too, but is absorbed by the next Totema, Adrammelech, who claims only his master may approach the crystal. After defeating him and shattering the crystal, Marche finds himself back in the cave where Babus Swain is waiting for him. Before Babus can do anything, another image of a pained Mewt appears. Babus asks Marche whether it is worth causing Mewt so much pain to revert the world.

Later at Muscadet, Marche finds judges taking away people for questioning, as they look for the people trying to destroy the world. When Marche sees a moogle being mistreated he runs in and claims he is who they are looking for. The judge sends in some units to see if he truly is whom they want. After defeating the units, Judgemaster Cid appears and takes Marche in for questioning.

Marche approaches a crystal.

While Cid wants to know why he is destroying the world threads, another portal opens taking in Marche, Cid, and Babus. Inside the chamber Marche concludes this Totema is severely weakened as the Exodus Fruit can do nothing. Babus claims he will not allow anyone to destroy the crystal and tries to defend Exodus. Upon destroying all the fruit and Babus, the crystal shatters, and Marche and Cid are exposed to a scene from their past, and Cid regains his memories. Now realizing what Marche is doing is right, Cid allows him to leave.

On the mission "Desert Patrol", Marche finds his brother, Doned, who has regained the use of his legs. Instead of being equally happy to see his older brother, Doned runs to the nearest clan group and turns Marche in. Dumbfounded, Marche fights off the group and wonders what is wrong with Doned.

During the mission "Quiet Sands" Marche encounters his biggest threat yet, the mysterious Llednar Twem, who tells Marche to leave the Delia Dunes. Before he can ask why, they are pulled into another crystal chamber where Llednar tries to kill Marche with his ultimate technique, Omega. Cid appears and uses an Anti-Law to disable it. The two engage in battle, but Marche is no match for him. When Llednar breaks a law Cid red cards him and sends him away.

Marche is confronted by the final Totema, Mateus, who tries to trick Marche out of his will to fight. When Mateus is defeated, the crystal shatters, but the world does not revert. Queen Remedi's voice proclaims that even without the crystals, the world will remain as long as someone wants it to. Realizing his friends want the world to stay, Marche sets out to convince them to revert the world.

Marche watches other people having a conversation about giving gifts. Montblanc explains it is because the Audience Day is approaching. Also known as Gift Day, it is a special day where everyone gives Prince Mewt gifts. Whoever has the best gift gets to meet him.

Marche and Ritz.

Knowing it will be a chance to talk to Mewt, the clan sets out to get a gift, some Materite. In the Materiwoods the clan is ambushed by a group of viera bandits who knew Marche would be there. Upon defeating the bandits, Marche realizes it must have been Doned who told them where to find him. Doned appears and claims he does not want to go back since he has nothing and Marche has everything, shattering the Materite the clan had come to claim. Doned runs off with Marche exclaiming Doned did have something he had always wanted.

They make a gift in time to present to Mewt with Nono's invention, the "lugaborg" (a possible reference to the boss "Lugaborg" from Final Fantasy IV). Marche is worried because Ivalice has a bounty on his head, but Montblanc tries to calm him down. Inside the palace they are ambushed in the waiting room by the castle guards. After dealing with the initial batch, Babus appears to help them, wanting to know more about the other world.

Taking them to the throne room, Marche approaches an angry Mewt and tries to reason with him, but is cut short by Queen Remedi, who teleports Mewt away. They are confronted by Llednar, who is invincible to anything they throw at him. Cid arrives scaring to run away. Babus and Cid promise to find where Mewt has gone.

While the others look for Mewt, Marche searches for his brother. He goes to a mythril vein and starts digging, which gets Doned's attention. After disposing of his goons, Marche tells Doned he always envied the attention he got and he wishes he was as loved as him. Doned realizes it is wrong to be selfish and agrees to help Marche revert the world.

After finding Mewt is hiding in Ambervale, Marche starts his trek there. On the mountain path he is confronted by his other friend, Ritz, who wants the world to stay and attacks. Upon her defeat, she accepts her fate and allows Marche's clan through.

Mewt prepares to send himself, Marche, and Cid home.

At Ambervale, Marche has a final engagement with Llednar, and using Ezel's ultimate Anti-Law, dispels his protection, allowing him to defeat Mewt's evil side once and for all. Inside Marche confronts Queen Remedi, and knocks her out. Marche begins to convince Mewt the world is not good for him and they should go home. Before Mewt can be fully convinced, Queen Remedi reveals her true form, the Li-Grim, the final world thread and the collection of all the world's wishes. Marche defeats her, convincing Mewt, who summons the Gran Grimoire and takes them all home.

Back in St. Ivalice, snow is falling and they learn to appreciate their lives outside the realm of fantasy. Ritz accepts her white hair after Shara tells her it is considered a blessing by the viera; Cid meets Biggs, his former business subordinate; Marche and Mewt defend themselves against Lyle, Guinness, and Colin. When they call Marche "New Kid", he asks them to call him by his real name. Doned gains will and helps another boy to play Final Fantasy.

Marche and Ritz.