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.

正式成为铁道部一员的大成，让高轮带着ERDA，知道了SHINKALION被开发的理由，还有失踪的姐姐伊奈曾经与SHINKALION的开发有关。

在这种情况下，不明之敌这次出现在良太的故乡敦贺。想用自己的手守护故乡的良太，不过，他的适应值不足……

正式に鉄道部の一員となったタイセイは、高輪にERDA（エルダ）を案内してもらい、シンカリオンが開発された理由、そして行方不明の姉・イナがかつてシンカリオンの開発に関わっていたことを知る。そんな中、アンノウンが今度はリョータの故郷、敦賀に出現。故郷を自身の手で守りたいリョータだが、彼の適性値は足りておらず……。