Guts is the protagonist of the story. He is a tall, muscular man with a huge sword called the Dragon Slayer, a prosthetic left forearm that has a magnetic grip which 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.

The protagonist of Shamo. As a child he was considered a genius, until one day he snapped and stabbed his parents to death. After being sent to juvenile prison, he learns karate to defend himself.
Ryo Narushima is consistently depicted as being unrepentant for the murder of his parents and is shown repeatedly committing morally repugnant crimes such as assault and rape. Though capable of redemption (as evidenced by his care-taking of his sister and various small charitable acts shown throughout the manga) ultimately Narushima is depicted as a Byronic hero spiraling into darkness, his chances at reform slowly ebbing away as he gives in to more and more of his depraved and brutal tendencies.