Kakugo no Susume

In a 21st-century Earth devastated by catastrophe, monstrous creatures and demons hunt humans. Kakugo and Harara were trained by their father in the Zero fighting style to safeguard the last humans and bring peace. Using advanced combat skills, hidden techniques, and armor forged from ancient warrior souls, they fight to protect people from violent creatures. After Harara falls to corruption, he kills their father and believes Kakugo is dead. Later, Kakugo arrives in a ruined city to aid survivors, defending them from monstrous threats. There, he confronts his now-deranged sibling, leading to a brutal clash redefining the meaning of family conflict.