New teacher Okada Yuu and his senior, Ms. Rumi are on a field trip with their 16 elementary students to Sanrio Puroland. But suddenly they wander into a mysterious and horrific theme park called "Yuropia"! Amid their confusion, ominous Frog Egg mascots announce that the only way for them to escape is to "conquer the attractions and gather 10 medals." Will they be able to get out of "Yuropia" in one piece?! This is a story for "those of you" who "carry pain in your heart".