Maimaimaigoen: Episode 1 - Welcome to Uropia

One day, the children and Okada Yu go on a field trip to Sanrio Puroland and find themselves lost in a deserted amusement park called "Uropia". They're bewildered by the unfamiliar surroundings when a mysterious creature Froggy Egg, appears before them. Suddenly, they're given an explanation of a "game"...

Okada and the children begin challenging various attractions within the park to beat the game and return to their original world. However, they're confronted with trials one after another...

Résumé

While on a field trip to Sanrio Puroland, Okada Yu and the children find themselves lost in the deserted amusement park Uropia. To return to their original world, they must challenge the attractions scattered throughout the park...