Umi is one of three school-aged girls running a jack-of-all-trades business, dedicated to funding their goal of purchasing a nearby island to establish an independent nation. She specializes in beauty services and event planning, showcasing a distinct entrepreneurial drive. Her approach is consistently business-minded, operating on the conviction that financial resources can resolve nearly any challenge. This perspective shapes her interactions and problem-solving methods during their ventures.

Within the group, Umi leverages her expertise in planning and beauty for diverse assignments, from practical tasks like lunch deliveries to complex social negotiations such as persuading behavioral changes. She relies on transactional thinking, treating financial incentives or costs as primary motivators.

A significant challenge arises when the group undertakes convincing a boy named Riku to return to school, despite none attending themselves. Umi participates fully, applying her characteristic framework of prioritizing practical solutions and resource allocation. Her interactions during this task remain anchored in her worldview, where monetary resolutions hold precedence.