Sarah is a central character in Gundam Build Divers, introduced as a mysterious AI-like girl connected to the GBN online game world. Gentle, curious, and emotionally expressive, she forms a close bond with the Divers and becomes especially important to Riku and his friends. Her role grows from a hidden presence into a key figure tied to the mysteries of GBN and the story’s larger conflict. Sarah represents the series’ themes of connection, friendship, and the blurred line between virtual life and real emotion.