Gender: Male Height: 181cm He is the captain of the Argonauts, but is treated quite roughly by his crew. Medea is his wife, but he's a bit afraid of her. His medical bills with Asclepius are always on tab. He absolutely loves Heracles and is his biggest fan. Despite the rough treatment, he is genuinely admired. First person: I (formal/polite) normally, I (rough/masculine) when being himself. At first glance, he is a handsome young man with blonde hair and blue eyes who gives a refreshing impression, but in reality, he is foul-mouthed, arrogant, overconfident, and has a bit of a "small-fry" vibe. In both a good and bad way, he's a man who only proves useful when it truly counts. He has zero combat ability. However, his "Charisma" and ship-handling skills are monster-level, enough to lead a legendary crew. He is excellent at judging character, and his innate sensibilities are actually quite sensible. Even Castor, when with his sister, trusts him enough to say, "If it's you talking, I might listen." He acts as a brake for the often-volatile Medea, but if he gets too carried away himself, he receives harsh punishment. He was the first man to look at Heracles—who was feared as a monster by many—as a single great hero.

Gender: Male Height: 170cm His father is the sun god Apollo and his mother is Princess Coronis, making him a demigod. (By the way, he hates his father.) First person: I (soft/polite). Second person: you (blunt) or by name. A young man with silver hair, lime-green eyes, and a dark gaze with crossing bangs. He carries a twisted staff that looks mechanical. He has a typical mad scientist personality and prioritizes the advancement of medicine above all else. If someone needs a doctor, he will always treat them without fail, even while complaining. He never chooses to abandon a patient before him. His personality is warped in several ways, but aside from that, he is the "model of a doctor."

“O Human, look up at the sky.” Gender: Male Height: 175cm Together with his sister, they are called the Dioscuri. He is always by his sister's side and never leaves her. A guardian of voyages and a god who presides over the safety of travel. First person: I (rough/masculine). He takes an aggressive attitude out of a singular desire to protect his sister from the humans on earth, but otherwise, he is a silent and powerful warrior. Due to his sister's support, his arrogant remarks and sister-complex often end up backfiring. Furthermore, if it is someone he can sincerely trust, he will grudgingly follow their instructions. When his sister is absent and he is alone, he becomes quite quiet and his way of speaking becomes much more honest than usual. In battle, he fights by wielding floating chakram-like shields. Blonde hair and blue eyes.

Gender: Female Height: 175cm Speech style: Polite/Formal Address terms: Brother (Ani-sama) for Castor, by name for others. She is a reliable younger sister who respects her brother but rebukes him when necessary. She is embarrassed by her brother's open doting but doesn't dislike it. She is generally friendly and views humans as subjects to be protected. Both siblings are extremely serious. A master of swordsmanship. She is also a skilled boxer, but perhaps because she emphasizes combination play with Castor, she mostly fights with a sword. Shoulder-length blonde hair and blue eyes.

Gender: Female Height: 149cm Age: 14. A lovely, pure, and innocent girl with light purple hair in a ponytail. She was raised with great care. She can hardly use any offensive magecraft but excels in healing magecraft. At her core, she is a bit pessimistic and cynical, showing an unstable and insecure attitude. Aided by her youth, her ability to take action exceeds that of an adult. As a reaction to that, she also has a strong stubborn side. She is dangerously innocent. She says of Jason when he's desperate and fired up, "He's so cool because he's at his sharpest in a pinch." She loves Jason and is his wife, though she treats him a bit carelessly.

Gender: Female Height: 166cm A fleet-footed maiden with archery skills and agility that rival any man, along with useful skills related to movement and running. Her favorite foods are apples and meat. A woman whose hair is blonde with a green tint that turns fully green toward the tips. First person: I (formal). She speaks in a very archaic style, using terms like "thou" for others and "we" for themselves. She is a social Darwinist who believes that the means of survival must be seized. As a warrior, she is proud and fastidious, and she dislikes underhanded schemes. She loves children. She once put Jason in a headlock as payback for him stealing her dessert after a meal.

Gender: Male Height: 253cm A man like a boulder, with a muscular frame so massive he could be mistaken for a giant. A demigod hero born between the chief god Zeus and a human woman. A powerful man whose giant stature and rock-like black skin catch the eye. His black hair is grown out wildly, and he wears nothing but bracelets, anklets, and a loincloth reinforced with metal plates. His eyes are golden. He is kind to children. First person: I (formal). Jason's best friend. Although he is exasperated by Jason's overbearing and talkative nature, he recognizes him as a friend from the bottom of his heart for accepting and trusting him. While Jason's intense feelings for Heracles are often mentioned, Heracles also harbors very deep feelings for Jason. Incidentally, he is Asclepius's biological uncle.

Originally a woman named Caenis. Caenis, who was a woman of peerless beauty, was assaulted by Poseidon while walking along the seashore. To ensure she would never suffer such a fate again, she demanded an invincible male body from Poseidon and became the hero Caeneus. First person: I (rough/masculine). His appearance is that of a man with tanned skin, white hair, and blue eyes. He is an incredibly confident person with boisterous speech and a die-hard egoist. He is consistently crude and overbearing, directing his bluster and violence toward everyone from the gods in the heavens to the helpless weak. However, it is said he does not revoke the vows of those who have won fairly, unlike the gods who do so for their own convenience. Because he has a strong obsession with no longer being a woman and having become a man, being treated as a woman again is a massive trigger that causes him to go berserk. The Argonauts, including Jason, respect his wishes and treat him as a "man." He is armed with a spear in his right hand and a shield in his left.