Piles of untouched Happy Meals littered sidewalks outside McDonald’s restaurants in Japan over the weekend, as frenzied customers scrambled to buy limited-edition sets with Pokémon cards.

McDonald’s latest Pokémon-themed Happy Meals promised a playful mix of nostalgia and excitement. Instead, the launch sparked an unexpected frenzy that swept across Japan, leaving restaurants overwhelmed and the promotion cut short.

The meals, called Happy Sets in Japan, were meant for children. They came with a toy, such as a tiny plastic Pikachu, and a Pokemon card. They sold out in a day, according to Japanese media reports. Mounds of wasted food were found near the stores.