In the story, Gaimetal, a metal ore with high amounts of pure energy, was discovered 50,000 meters (160,000 feet) underground in 2047, and mining began all around the world. However, Gaist, metallic lifeforms whose bodies are entirely encrusted with Gaimetal, emerged in 2055 and began attacking people. In 2064, Rekka, Hayato, Kurama, and Siren are among those who suit up in Gaist Gear and battle over 100 varieties of Gaist creatures.
Seiyuu
Spoiler for seiyuu:
Daiki Yamashita as Rekka Shirogane
Makoto Furukawa as Shiren Quartzheart
Yasuyuki Takase as Kurama Shindō
Yūichi Iguchi as Hayato Konkōji
Asami Tano as Kohaku Kondōji
Ayahi Takagaki as Luminella Hotaru
Katsuyuki Konishi as Volcan
Kenichi Suzumura as Cypher
Kentarou Tone as Dr. Magnus
Michiyo Murase as Jinta Atō
Risa Taneda as Sango Sakura
Sora Amamiya as Hisui Midori
Tsuguo Mogami as Zeke Bana
Ai Terashima as Ken Nitta
Baron Yamazaki as Yu Chitasaki
Daichi Nomura as Gus Tennen
Issei Futamata as Haijirō Haino
Kikuko Inoue as Hinoko Shirogane
Megumi Han as Rin Shirogane
Shinya Fukumatsu as Gōka Shirogane
Tetsuya Yanagihara as Densuke Aburaya
Staff
Spoiler for staff:
Director: Nobuhiro Takamoto
Series Composition: Satoru Nishizono
Music:
Kouhei Tanaka
Takayuki Negishi
Character Design: Yukiko Ishibashi
Art Director: Eri Inoue
Chief Animation Director: Yukiko Ishibashi
Mechanical design: Hideki Fukushima
Sound Director: Rika Ishibashi
Director of Photography: Nobuo Kimura
Color design: Aiko Shinohara
Editing: Takeshi Seyama
Sound Effects: Yasuyuki Konno
Theme Song Arrangement: Takayuki Negishi (OP)
Theme Song Composition: Kouhei Tanaka (OP)
Theme Song Lyrics: Seiko Fujibayashi (OP)
Theme Song Performance: Hiroshi Kitadani (OP)