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...