Selene is highly curious and easygoing Trainer, she worries about some little things and tends to act on instinct or by impulse.

Selene is native to the Kanto region and currently resides in Alola's Route 1 in the Hau'oli City Outskirts, with her mother and a Meowth. The Professor Kukui considers her and Lillie to be Selene's neighbor.

During her travels, She encountered a group of pale people known as the Ultra Recon Squad, who are later revealed to be working with the Aether Foundation. When Lillie and Nebby were kidnapped, Selene followed them and finded out that Lusamine, was seeking to travel to Ultra Megalopolis to stop Necrozma before it can threaten Alola. She used Nebby's powers to travel to this alternate world, leaving them to figure out how to follow her. They traveled to Poni Island and performed a ritual that caused Nebby to evolve into Lunala, but Nebby was kidnapped by Necrozma but with the help of the Ultra Recon Squad, they managed to defeat it and save Nebby.

After completing the last island challenge trial, Selene climbed Mount Lanakila to reach the established Pokémon League, re-encountering Necrozma along the way. After She has defeated the Alola Elite Four, Professor Kukui arrived and presented Hau as her final challenge before she claim the championship. Selene successfully defeated Hau one last time, making her the first Champion of Alola.

She assisted the Ultra Recon Squad in catching some Ultra Beasts. But no sooner has he returned home, he learned of the Team Rainbow Rocket appearing. The team taked over Aether Paradise, and kindnaped Lusamine. But Selene taked down the members of Team Rainbow Rocket, including their leader, Giovanni, saving Lusamine and making Team Rainbow Rocket leave Alola.

She currently was in the poarch of her house, looking a the sunset.

"And there goes another day..."