South of the town's Seagallop Ferry dock is a short watery path to Treasure Beach, while east of it is the challenging Kindle Road. As it is such a small town, many more things can be done on these two routes than in the town itself, though players will find themselves brought back here repeatedly in their quest to use the Ruby and Sapphire to complete the Network Machine.
One Island's total population is 10. This excludes Bill and the Pokémon Center lady, but does include Celio. The population is very small, because many young people move away to big cities in Kanto.
A colored background means that the Pokémon can be found in this location in the specified game. A white background with a colored letter means that the Pokémon cannot be found here.
One Island appeared in The Search for the Legend, where a boat Ritchie was traveling on briefly stopped there. He learned that the town had been evacuated, as Mt. Magma was expected to erupt soon.
In Now You See Me..., Red, Blue, Green, and Bill all boarded the Seagallop to One Island. Green was travelling to reunite with her parents, who had relocated there. Just before the Seagallop docked, Green was attacked by an invisible Pokémon, which also trapped her parents in a black hole. Overcome by trauma following the incident, Green was taken to the Pokémon Network Center to recover. Meanwhile, Red and Blue encountered Ultima, who took both of them to Two Island to learn her ultimate moves in order to combat the unseen opponent better.
In Don't Doubt Deoxys, a mob tried to storm the Network Center, as Team Rocket was attacking the Sevii Islands to capture of the Pallet TownPokédex holders, and the mob wanted to hand Green over to them to make the attack stop.
In Some Things Are Better Left Unown, the Seagallop ferried Ultima back to One Island on her request. It picked up Green, who had recovered enough and was escaping from the mob after her, and took her and Ultima to Five Island to reunite with Red.
