Apocalypse Zero

Kakugo, a young boy, possesses impressive martial arts skills and a powerful suit of armor left to him by his father. This inheritance is matched by his sister, who also has exceptional abilities and equipment. However, their goals are vastly different, with Kakugo seeking to protect his school and others, while his sister aims to eradicate humanity. The series revolves around their contrasting motivations in a post-apocalyptic world ravaged by natural disasters.