A phantom beast that has almost conquered Okinawa and Kyushu, and continues to advance to the Chugoku region. The 7th Shibamura Squadron of the 105th Division, which stopped it, was a special unit made up of dragoons with animal soldiers called Raiden. However, one day, headquarters ordered the 7th Shibamura Company to withdraw. Unsatisfied with the headquarters' orders, Gen remains alone in the mountains to confront the phantom beast...