Booker, an expert carpenter, is first met shortly after the player washes up on Dolce Island where he was investigating UFOs that were flying around the island. After he introduces himself, Booker offers to take the player to his home in Cocona Village in an unfinished boat of his. Booker has a grandson, Ralph, who also lives in Cocona Village. Later on in the story he is called upon to fix Big Booker Bridge after the Pokémon Pinchers damage it.
He makes ships for a living along with his apprentice Nick. In case the waves get high on Dolce Island, he looks after the Pokémon unable to swim or fly by creating refuge boats on the island to keep them safe. When the Pokémon Pinchers damage the Big Booker Bridge, he notably repairs it in a short amount of time, which is attributed to him designed the bridge. One of his prized ships is The Union, which later on in the game is docked at the Tilt Village harbor for the player to use. Another creation of Booker is UkulelePichu's ukulele, which was made of spare ship material. He gave Pichu the ukulele as a token of his gratitude for making him feel better whenever he got tired of creating the boats on Dolce Island. Pichu's nickname of Ukulele Pichu was also given to it by Booker. Booker also assisted in evacuating the Pokémon from Dolce Island just before the Sky Fortress vaporized it.