Britney Melissa Kasandora is the middle child of Maxie & Olympia Kasandora. She was born prematurely and not expected to survive, but she was injected with the Life Energy of Xerneas, rendering her immortal. As a result, she lights up a dazzling shade of pink whenever she is touched. Britney had joined her eighteen year old brother, Ethan, and was later joined by her half-sister, Winona, her half-siblings Tate & Liza-Lan, and her youngest sibling, Emerald. A year after Emerald's birth, Olympia was banished to the Kalos region for "conspiracy," leaving Emerald, Britney and Ethan back in Hoenn.
Growing up, Britney and her older brother were deemed inelegible to become leader of Team Magma, that position falling to their half-sibling, Winona. Britney quickly became engaged to Gladion Dresden, the 15 year old son of Guzma and Lusamine Dresden, igniting the rage of both Maxie and her stepmother, Courtney. Maxie revealed that he never should've dated Olympia, and blamed her for the births of Britney, Emerald & Ethan, before banishing Britney to Kalos. Though Winona and her boyfriend, Tabitha Homura, try to reason with Maxie, as they truly love Britney, nothing can change his heart. He also orders Tabitha to kill Gladion, but he can't bring himself to hurt him, and instead, takes him and Britney to Kalos.