|Full Name: Mio Natsume
|Ranger Designation: ToQ 3gou
|Gear: Shingo Hammer, ToQ Blaster, ToQ Changer, Rainbow Pass
|Ressha: Yellow Ressha, Car Carrier Ressha, Wild Cat Reesha
|Mio is a sporty girl, really good at housework and often seen taking care of everyone else. Because of her housework skills, she is quite popular with the boys but she is very uncomfortable with the idea of romance. Mio acts as the team's big sister and usually the one keeping everyone in line, and has absolutely no tolerance for under-handed attacks. As ToQ 3gou, normally colored yellow, she uses the railway signal-themed Shingo Hammer as her weapon. When Emperor of Darkness Z's darkness as well as the Shadow Lines invaded Subarugahama, their home, Mio and her friends were taken away by the Rainbow Line light. She also had an imagination friend/shumai-themed doll, Mikey, which only Hikari aware of. In one incident, Hammer Shadow materializes Mikey, her imaginary friend, from her and tried to dispose him to bring Mio into despair. However, thanks to Mikey's mischievous nature, it escaped barely before protecting Mio from Hammer Shadow. Instead of felling into despair, Mio spirited and managed to attack Hammer Shadow before the latter being saved by General Schwarz. Her full name is eventually revealed to be Mio Natsume whose father Kohei is a police officer. She has become every color of her team mates except for Orange.