After Sentouin D successfully penetrated the Ranger Force disguised as Hibiki Sakurama, he is nearer than ever to vanquishing the valiant Dragon Keepers.
While plotting his optimal role within the organization, he learns that he has been placed in the Green Squadron, whose chief responsibility is to locate and eliminate long-extinct boss monsters.
Accompanied by a fresh recruit, Angel Usukubo; their superior, Kanon Hisui; and an enigmatic source, Chidori, Sentouin D is initially assigned to detect odd occurrences at a derelict school popular with troublemakers.
While probing the scene, they are lured into a snare, and the team quickly discerns that a boss monster orchestrated the ploy.
Sentouin D must now devise a means to flee with his comrades if he wishes to keep chasing his ultimate aim—crafting a flawless world devoid of boss monsters and the Dragon Keepers.
