Futaba Mihara is a recurring character who works for the Shinkansen Ultra Evolution Institute at its Omiya Branch. She first appears as an operator, a role in which she coordinates field operations and provides mission support to the pilots of the Shinkalion robots. Her duties are crucial to the team's functioning, as she helps manage the logistics of their battles from the command center.

Her background reveals a long-standing connection to the railway organization, as flashbacks depict her childhood and show her early ties to the institute, illustrating her path to becoming a dedicated staff member. The meaning behind her name reflects the series' railway themes; her surname, Mihara, is derived from a station on the Sanyo Shinkansen Line, while her given name, Futaba, comes from a discontinued semi-express service on the Sanyo Main Line.

Within the story, Futaba's role evolves significantly. When the Omiya Branch's director, Hokuto Hayasugi, is transferred to the Kyoto Branch, she steps in to become the acting director. This promotion marks a major increase in her responsibility, requiring her to oversee the branch's operations and personnel. Her leadership is formally recognized when she is officially promoted to the position of director of the Omiya Branch. Her responsibilities extend beyond tactical coordination to include overseeing and mentoring the child pilots, particularly during critical threats. The series also offers occasional glimpses into her personal life outside of work, including a look at her apartment.

Futaba does not pilot a Shinkalion herself, so her notable abilities are not combat-oriented. Instead, her strengths lie in her operational expertise, strategic coordination, and leadership. She is a consistent presence in the series, maintaining her role as a support leader and mentor from her first appearance and throughout major story developments.