• English / United States: Sarah
• Japanese / Japan: スイ
• Japanese (Romanized) / Japan: Sui
• Japanese (TL) / Japan: Sui

Sui is one of Lana's little sisters. Ho and Sui are twin sisters. She lives in the Alola region within walking distance of the Pokémon School. Ash Ketchum visited their home one day after school and she thought that he might be Lana's boyfriend but was then quickly interested in Ash's Pikachu. After a few moments of fooling around with Ash's Pikachu, it got annoyed and Thunderbolted everyone in the house. She can often be identified by the Shellder graphic on her shirt.