"Unknown" is a mysterious enemy that suddenly appeared a long time ago. As a countermeasure, the "Evolutionary Railway Development Agency" (ERDA) has developed the "Shinkalion" robot that transform into bullet trains, to prepare for the threat. "I want to be a cool person who can protect something..." Taisei Oonari, a second-year junior high school student, transfers to Shinkai Gakuen Middle School in search of clues about his older sister who disappeared two years ago. <Show more