Midori Matsumura is a genetically engineered teenage super-soldier, a product of the Wet Prope military project designed to pilot large mechanized Skelters. She serves within an all-female pilot unit under the Alta Mira Agency (AA Company), tasked with defending Tokyo against hostile squid-like alien entities by operating specialized mechanized combat units called Battle Soles. Identified by her purple hair, her combat role incorporates archer-themed elements. Her artificial existence results from the project's successful pivot to female subjects after initial failures with male candidates. Her mission performance and interactions, influenced by training efficiency and relational dynamics, contribute to variable story outcomes. She operates alongside other genetically engineered pilots under Commander Otsuya Funagai, with narrative progression shifting based on dialogue choices and battle performance, particularly through the Interactive Command Assist system where timely inputs affect mission success and interpersonal developments.