Taisei, who has officially become a member of the Railway Club, is given a tour around ERDA by Takanawa, and learns the reason why Shinkalion was developed, as well as the fact that his missing sister, Ina, was once involved in the development of Shinkalion.

Meanwhile, the Unknown shows up in Ryota's hometown, Tsuruga this time. Ryota wants to protect his hometown with his own hands, but he doesn't have enough Aptitude Value.

In preparation for more Unknowns to appear, Taisei stays in Tsuruga and enjoys the railway museum he once visited with his sister.

Meanwhile, Ryota is training alone to raise his Aptitude Value.

Ryota has a strong admiration for the Shinkalions because a Shinkalion saved his life when he was young. Although he feels regretful that he was unable to protect Tsuruga with his own hands, he still hides his true feelings.