Taichi, Jou, Agumon, and Gomamon ride a swan boat towards the Digivice's signal. After landing, they find themselves at a large Japanese-style castle, where they find the place swarming with Gekomon and Otamamon, frog and tadpole Digimon. The Gekomon and Otamamon run around frantically, trying to please a "princess" who seems to have incredibly fast-changing desires. A fanfare announces the arrival of the princess... and the princess turns out to be none other than Mimi, wearing a very pretty pink and white princess gown, gold crown, and holding a fan!
PicoDevimon reports to Vamdemon, telling him that the Gekomon are treating Mimi like a princess and that, because of that, her Crest of Purity will never activate. Vamdemon threatens PicoDevimon with more punishment if he fails and vanishes.
Taichi tells Mimi to change and get ready to head off with them, but Mimi is so happy to be treated like a princess that she refuses to leave, reasoning that there's no guarantee they can return to their world anyway. Not helping the situation is Palmon, who comes into the room wearing another frilly princess dress. On Mimi's orders, the Gekomon kick Taichi, Jou, Agumon, and Gomamon out of the castle.
The Gekomon, however, reveal that they're not completely happy with being at Mimi's beck and call; they lead the four to a large sleeping Digimon, whom they refer to as their "lord". Supposedly, he had been sleeping for over three hundred years after having lost a karaoke match, and that the only way to bring him back is for him to hear the voice that is lovelier than the one he lost to. As a result, they tried to recruit Mimi to sing for them (who, incidentally, sings "I Wish" for no real reason other than her voice actress, Ai Maeda, being the singer of the song), who was able to get the lord to stir before she froze up and forgot the words. Trying to get Mimi to remember the lyrics, the Gekomon and Otamamon began to spoil her, until her demands started to get ridiculous, but had to cater to them under her threatening to be unable to sing for them if they are not met.
Taichi, Jou, Agumon, and Gomamon try to take matters into their own hands (and claws and flippers) and sing the song themselves, with... less than stellar results. Palmon enters and, when asked, agrees that Mimi has been acting strangely. With that, they hatch a plan to have Palmon have Mimi sing in her room and have Taichi take a recording of it, but Mimi catches onto it and throws all five of them into the dungeon after exposing the trick. An exasperated Palmon yells that she hates Mimi, to which Mimi responds in kind before storming off with the saddened Gekomon to continue her lovely princess life, and them having to cater her requests for possibly forever without her ever fulfilling her promise in return.
Mimi dreams that night of Devimon and Etemon coming to get her, and of the Gekomon and Otamamon deserting her for not making good on her promise to sing for them, even when she pleads that she'll do it if they don't walk away, and of Palmon and her other friends leaving her for what shes done to them as well because of her selfishness and insincerity. Mimi then sees Sora over her bed, who tells her to fix things. Mimi gets up to see her Crest of Purity glowing... and Sora gone.
Taichi and the others are freed from the dungeon to see Mimi standing back on stage with her normal clothes on, and Mimi apologizes to everyone for her selfishness, being a jerk, and is on the verge of crying if forgiveness is not something on everyone's minds. However, everyone forgives her, and Mimi sings the song to completion, waking up the giant Digimon, TonosamaGekomonnote , but to everyone's horror, TonosamaGekomon isn't very happy to have been woken, and immediately starts attacking everyone. The panicked Gekomon and Otamamon realize that waking him up was a mistake, and Palmon evolves to Togemon to fend them off, joined by Greymon and Ikkakumon.
TonosamaGekomon turns out to be stronger than he looks, and Taichi super-evolves Greymon to MetalGreymon, who finishes off TonosamaGekomon. Unfortunately, Togemon won't super-evolve quite yet.
Meanwhile, PicoDevimon receives his just desserts for having failed to stop the Crest of Purity from activating after being warned earlier for if he failed again by Vamdemon...
- Didn't Think This Through: Upon seeing that their lord is a tyrant, the Gekomon and Otamamon realize that waking TonosamaGekomon wasn't the best idea.
- Dreadful Musician: In an attempt to get Mimi back, the others try to wake TonosamaGekomon themselves. Unfortunately, Taichi is off-key, Jou's singing is clumsy, and Agumon and Gomamon's duet is so terrible that Taichi, Jou, and the Gekomon have to cover their ears.
- Not a Morning Person: The dub changed TonosamaGekomon's reason for rampaging to waking up cranky rather than being Evil All Along.
- Sequence Breaking: The episode seems to be leading up to Togemon super-evolving to defeat TonosamaGekomon, following the pattern of the previous two episodes, only for a Bait-and-Switch to be pulled and MetalGreymon to be the one to defeat him, with Togemon not super-evolving till a while later.
- Sore Loser: TonosamaGekomon went to sleep for 300 hundred years after he lost a karaoke contest.
- Stronger Than They Look: As Jou stated, TonosamaGekomon might look like a Fat Idiot Bastard, but he's actually pretty strong, though not enough to beat MetalGreymon.
- Took a Level in Jerkass: Mimi, after the Digimon's adulation gets to her head and turns her into a demanding tyrant. She gets better.
- Ungrateful Bastard: TonosamaGekomon didn't appreciate being woken up, and went on a rampage in response. Mimi calls him out on it.
- Xanatos Gambit: It's hinted that PicoDevimon knew that TonosamaGekomon was a tyrannical ruler, and thus that if Mimi didn't become a Spoiled Brat from the royal treatment then TonosamaGekomon would've killed her upon waking up.