BBK/BRNK

Azuma Kazuki returns home after a decade abroad, only to be ambushed and taken captive by heavily armed individuals. He's soon rescued by Kogane Asabuki, his childhood friend, who possesses a sentient arm-mounted weapon called Bubuki. Upon his escape, Azuma discovers he too can control Bubuki, which sets him on a course to revive the Buranki titan Oubu, said to be buried deep beneath the earth. This newfound goal reveals a path for Azuma to uncover the truth about the Buranki.