The year is 1989. After the nation of Hinomoto was destabilized during the past World War, the rise of new technologies has enabled its revitalization. Modern engineering has given birth to aircraft, gasoline engines, and geomagnetic technology—revolutionizing transportation. Railroads have been rendered nearly obsolete and replaced by more efficient modes of transit. However, a group of lively Raillords aims to renew the railroads' former glory. The Raillords, personified as energetic and spirited girls, act as humanoid control modules for their assigned railways. They meet in Ohitoyo City for the Raillord Summit, headed by Suzushiro, a Raillord from Manoka Railways. Together, the group capitalizes on its teamwork to get the railroads back on track, ushering in a new railroad age.

Atsushi Miyagawa is an 11-year-old boy with the appearance of a fully-grown man. His 17-year-old sister, Atsumi, has the stature of a child! From Atsushi being arrested numerous times as a suspected predator to Atsumi constantly grabbed like a small child more times than she can count, many things go wrong for this curious sibling duo. Atsumi's classmate is even in love with Atsushi, oblivious to his true age! Despite all this, indeed, there is not a single dull moment in the Miyagawa household.

Third season of Recorder to Randoseru.

Unaired episode 13 included on the Blu-ray/DVD volume of the Recorder to Randoseru Mi☆ series.