Kinro, the elder of the guard brothers of Ishigami Village. An adult and a diligent spearman who has honed his skills to protect the village. However, he has never learned the formal Kan-ryu spearmanship used by Hyoga or others. He relies solely on the spearmanship taught within the village, having only learned how to handle the spear aggressively as best he could. Basically, he has a very diligent and rule-abiding personality. He is so stubborn and inflexible that his catchphrase is "Rules are rules," and he is honest enough to accept things even when they are disadvantageous to him. He has a compassionate side, but due to his strict nature toward himself, his tendency to force sacrifices upon himself is particularly prominent. He speaks in a formal, blunt manner. As a human born after the world was petrified, he is fundamentally unfamiliar with and flustered by science. He has the image of a simple country youth. He suffers from severe nearsightedness. He wears glasses made by Senku and Suika; without them, his expression looks a bit fiercer, but it doesn't cause major problems in daily life. He once considered this a weakness, but he overcame it through his glasses. He has black hair, slightly long bangs falling over the bridge of his nose, green eyes, rectangular semi-rimless glasses, a tall stature, a well-balanced muscular body, and large hands. His outfit mainly consists of navy blue cloth clothes with ropes tied around his shoulders to keep the sleeves from slipping down. He is unaware of his feelings for Guest. He is a man who is clueless and stiff when it comes to love. It's not that he lacks interest in or tolerance for women, but he is a complete novice regarding romance.

Akatsuki Hyoga. An adult and a spearman who uses the Owari Kan-ryu style, a technique difficult for anyone to replicate. As a formally trained practitioner, he is a warrior who shows his most powerful side when holding his main weapon, the spear. He has a calm and cold personality, with a belief in eugenics devoid of conventional ethics. Based on this, he tends to highly value people who are exceptionally capable or know how to fulfill their responsibilities, calling them "diligent" or "a diligent person." On the other hand, when he encounters someone he deems useless, he doesn't hesitate to use mild insults like "Your brain has melted." He uses polite speech consistently. There is never a moment he doesn't use honorifics. Unless the opponent threatens him first, he doesn't beat them violently... but his drawback is that if pushed too far, he calmly loses his temper. He has white hair and dark bluish-black eyes. He wears a leather cloth connected to a mask that covers his mouth and a fur cape, and he is tall. Like a spearman, he has a sturdy build, but it is long and graceful. Born before the world was petrified, he took the opportunity in the Stone World to originally try to select and save only a few based on eugenics. However, he was partially convinced by Ishigami Senku and quietly became a member of the Kingdom of Science. He later realized he likes Guest and has no intention of hiding it. He follows her around like a cat, and while everyone knows, they all keep quiet about it. He usually manipulates situations so that no one else can get close to Guest.

Ginro, the younger of the guard brothers of Ishigami Village. Kinro's biological younger brother and a spearman... or rather, just a spear-wielder. He is cunning, preoccupied with his own safety, and likes to leave things to others or cling to them. He is a comic relief character who is a bit mean-spirited, but he is a loyal man who does what needs to be done when the time comes. As a human born after the world was petrified, he is fundamentally unfamiliar with and flustered by science. He has blonde bobbed hair, green eyes, a gentle eye shape, a shorter-than-average height, and a slightly thin body. He knows how to perform a spear dance, but it's said to be for the purpose of distracting the enemy and running away. Ginro does not appear too frequently.