Rudo Surebrec (ルド スレブレック) .
Rudo Surebrec is a 15-year-old boy born and raised in the slums of the floating city called the Sphere. He is the adoptive son of Regto, a kind man who raised him with care despite their harsh surroundings. Rudo's biological parents were criminals exiled to the Abyss before his birth, and their legacy haunts him, symbolized by the painful scars on his arms. Living among the "tribesfolk"—descendants of exiled criminals—Rudo grew up despising the wealthy upper class who live in luxury above while discarding their trash and unwanted people into the Abyss, a massive pit beneath the city. One day, returning home, Rudo finds Regto fatally stabbed. Authorities immediately accuse Rudo of the murder without investigation, sentencing him to exile in the Abyss. Instead of dying, Rudo discovers the Abyss is a vast, dangerous wasteland filled with monstrous creatures born from trash. There he's saved by Enjin, a member of the Cleaners—a group that fights the trash monsters. Rudo learns he has a rare ability as a "Giver," able to imbue discarded objects with power, turning them into weapons called Vital Instruments.