Oicho emerges among a band of street children in the Restricted Area, closely linked to Sachio and their makeshift family. Initially a background presence with sparse dialogue in the first season, her narrative importance grows as the story unfolds. By the second season, she takes up an apprenticeship with Abuhachi, training as an engineer in his repair shop. Here, she hones her technical expertise through equipment maintenance and mechanical problem-solving, evolving into a vital support pillar for the group. Her contributions center on collaborative projects with the core team, where her skills prove indispensable in sustaining their operations and fortifying their collective resilience.