Guts is the protagonist of the story. A tall, muscular male with a huge sword called the Dragon Slayer, a prosthetic left forearm that has a magnetic grip, and also conceals a cannon. Guts is a tragic hero; he is born as one who may be able to struggle against Causality, but seemingly unable to affect it on a large scale.

Yagami Light is a brilliant college student. Nicknamed as "Kira", he uses the death note to create his ideal world of justice under him; its new god. Though he looks frail, Light is an extremely athletic person, with an aptitude to find an opponent's weak point. He is a genius, which adds to his notion that only he is fit to judge humanity and steer it on a proper moral course.