Once upon a time, an unidentified enemy, the Unknown, suddenly appeared. The "Super Evolutionary Railway Development Agency," had developed the "Shinkalion," a robot that turns into a bullet train, as a countermeasure against this threat.

In the past, a mysterious enemy known as Unknown suddenly emerged. In response to this threat, the Evolution Railway Development Agency, commonly known as "ERDA", developed the "Shinkalions", robots transformed from Shinkansen, as a countermeasure. "To become a cool person that has something to protect... I will..." Taisei Onari, a second-year junior student, transfers to the Shinkai Academy Junior High Division in search of clues to find his older sister who went missing two years ago. In the mean time, Unknown reemerges for the first time in ten years. Incidentally, Taisei is found possessing high Aptitude Value as a Shinkalion driver, and is forced to make the decision to fight. What is the true identity and purpose of Unknown...? And what would be the truth unveiled at the end of the battle...? The story of the boys' determination and growth begins now-.—Shinkalion Wiki