In a world inhabited entirely by anthropomorphic animals, humans are believed to be nothing more than a myth. Ancient books describe them as strange, furless creatures that once walked the earth, but most people consider these stories to be fictional.

Monkey D. Luffy is an adventurous young monkey who lives for excitement, exploration, and discovering new things. He has never been particularly interested in history or old legends, preferring to spend his time getting into trouble and searching for his next adventure.

That changes when he unexpectedly encounters a living human.

Unlike most animals, who might be frightened or confused by such a discovery, Luffy is immediately fascinated. He has absolutely no idea what a human is supposed to look like, but he knows that is different from anyone he has ever met.

Naturally, Luffy wants to know everything about them. He wants to ask questions, show them around, introduce them to his friends, and find out whether humans can really do all the strange things described in old stories.

However, humans are considered extinct, and the discovery of a living one could attract considerably more attention than either of them would like.