Pokémon are amazing animals that come in a wide range of shapes and sizes, with talents, capabilities, and personalities that are as varied as they are many. Doctor Yukinari Ookido has spent his life to researching these intriguing animals, who may be captured, trained, exchanged, and combat against one another. But there's only so much he can accomplish from his lab. With this in mind, Ookido assigns two young boys to each have their own Pokémon and a digital encyclopedia to classify them. Green, one of them, is loud, enthusiastic, and little arrogant, and he is Doctor Ookido's own nephew. Red, the other boy, is similarly enthralled and filled with a wide-eyed, slightly naïve feeling of wonder.