Captured by Neptunemon, Archelomon is forced to give up the whereabouts of the Code Crown. In order to protect it, Mikey and the others head into the stomach of the gigantic King Whamon.
The Fusion Fighters eventually learn of Archelomon's capture. Meanwhile, the Summer Harvest is over, and the island, who is King Whamon, moves. Chibitortomon tells them that once a year they give KingWhamon DigiBytes for protecting their Code Crown. They then notice several Flymon carrying food hiding dynamite. Realizing that this would harm KingWhamon, the Fusion Fighters attempt to destroy them. Syakomon attempts to snipe the dynamite, and Shoutmon hurts himself severely by physically taking care of those Syakomon misses.
After several rounds of this, the Flymon realize that their plan is not working and prepare to attack Shoutmon and Mikey. Suddenly, King Whamon opens his mouth, and the Flymon invade as Mikey and Shoutmon are drawn in. Mikey and Shoutmon then realize they are in KingWhamon's stomach, and set out to find the Code Crown, though they eventually come across the Flymon. One of the Flymon stings Shoutmon, who gets sick afterwards.
Meanwhile, everyone on the island prays to King Whamon that Mikey and Shoutmon will be safe. When the Flymon try to grab the Code Crown, a force repels them. King Whamon then tells Mikey to hold onto something. Mikey quickly grabs Shoutmon and does so, and then King Whamon takes in water to expel the Flymon in his body. When Mikey explains the situation, King Whamon drops some goo and tells Mikey to apply it to wound, and Shoutmon is quickly healed. After also explaining his intent to defy Lord Bagra, King Whamon also gives Mikey possession of the Code Crown and sends him on his way.
Neptunemon sends an Ebidramon to attack them. Mikey sends Shoutmon X2 and the Star Axe to fight, but Ebidramon is still too strong for Shoutmon X2 to handle. King Whamon then informs Chibitortomon of additional treasure hidden beneath him, which Chibitortomon discovers are five DigiCards. He takes them to Mikey, who then summons the DigiCard of Leviamon, who cripples Ebidramon enough for Shoutmon X2 to destroy him.
As the Fusion Fighters celebrate their victory, Neptunemon sends his fleet of Seadramon to attack them.
(Numbers indicate order of appearance. Bolded characters are fought by the protagonists, and italicized characters appear only as a voice or silhouette.)
Dondokomon Type: Musical Instrument Special Moves Dondoko March Dondoko Rush Extreme Taiko
Monitamon: "Dondokomon. Dondokomon is a Musical Instrument type Digimon. His special attacks include "Dondoko March", "Dondoko Rush", and "Extreme Taiko". This peppy, percussive, party-loving Digimon fires up his allies with his irresistible pulse-pounding rhythms. Problem is, he fires up his enemies, too. End result: total chaos! Well, what do you expect from someone who hits himself on the head all day?!"
Dondokomon Type: Musical Instrument Special Moves Dondoko Ondo Midareuchi Rush Kiwame Daiko
Monitamon: "Dondokomon. Its techniques includes raising the spirits of both enemy and ally Digimon alike with "Dondoko Ondo". It cheers up the enemy Digimon too?! Well, I'm all up myself! 'Stand up, my friend!'" Shoutmon: "We Are Xros Heart?!"