"Cross Zone" is a world beyond human knowledge where one world and another world intersect. ~ This time, an incredible event that Tatsuhiko (6th grader) and others encountered on Ryugashima on a school trip. The place where I stepped into with a little sense of adventure was a "cross zone" with the ancient world. A sci-fi adventure written in 1992 that was expressed and announced in manga earlier than the movie "Jurassic Park" that surprised the world and made a big hit.