Haruka Suenaga is Mirai's younger sister and a top student at school and an electronics genius who has a strong sense of responsibility, but also loves getting up to mischief and often plays pranks on others. Sharing the same interests as her sister, she became the head member of the Asakusa Metropolitan middle school newspaper club and hence often works closely with the high school news club. Her close relations with the high school news club inevitably leads to her involvement with the Solar Marines.
