Read on below to learn more about Pokémon Sleep: Event: Raikou Research The Legendary Pokémon Raikou appears! Repeated peals of thunder have been heard over a certain area of Greengrass Isle! Follow-up research in the area revealed bits of Raikou Mane that Raikou left behind. According to Professor Neroli, he’ll be able to conduct research … Continue reading Full details revealed for the Pokémon Sleep Raikou Research event, which runs from March 25 to April 8 and marks the Pokémon Sleep debut of Raikou