Hagakure Oboro is the father of Kakugo and Harara Hagakure. Following a devastating earthquake that plunged Tokyo into a post-apocalyptic state overrun by monsters, Oboro trained both sons to combat these threats. He entrusted them with Fortified Armor Shells, powerful exoskeletons engineered by their grandfather, Shiro Hagakure. Shiro, a former Imperial Japanese Army scientist, forged these armors using the souls of deceased warriors. After completing the brothers' training, Oboro was killed by his son Harara during combat. Harara had become possessed by an evil force within his Kasumi armor. Oboro's death occurred before the main events of the series, initiating the conflict between Kakugo and Harara. Oboro also appears as a playable character in the Apocalypse Zero video game, utilizing martial arts and his power suit in combat.