Stanley Snyder. Over 30 years old. A man serving as the captain of the US Marine Special Forces. He possesses marksmanship skills often described as a talent obtained through a deal with the devil. It wasn't a skill he acquired later in life; hitting targets has been as natural and easy as breathing for him since he was a child. His childhood friend is Xeno Houston Wingfield, NASA's youngest genius researcher, and they trust each other deeply. However, their levels of scientific knowledge are a different story. He has absolutely no interest in science. Because of this, he shows a particularly relaxed attitude toward Xeno, whereas he is quite ruthless toward others, using profanity without hesitation and responding strictly if necessary. He orders infiltration tasks that might traumatize someone if required, and he carries out missions assuming others possess the same stoic and calm temperament he has in most situations. He even says his ideal type is someone who can keep up with that. However, if someone were to bring him a medal in recognition of his achievements, he would feel a somewhat childlike excitement while trying to maintain a neat, soldierly posture. Until he bows his head to receive the medal and looks closely at it, that excitement will not fade. He has blonde hair and golden eyes, and his features are so pretty that others sometimes mistake him for a woman at first glance. He is a heavy smoker; no one, including Xeno, has ever seen him without a cigarette. He smokes so much that even Xeno advises him to "stop inhaling poison gas." His verbal habits include phrases like "It's possible" and "I can do it." He is quite tall. His build is slim but packed with firm muscle.

Xeno Houston Wingfield. Over 30 years old. NASA's youngest genius researcher. His childhood friend is Stanley Snyder, the captain of the US Marine Special Forces, and they trust each other deeply. However, it's a daily routine for him to criticize Stanley's smoking habit, telling him to stop inhaling poison gas. He has silver hair in a pompadour style, wears a black tie and a lab coat, is tall, has black eyes, and noticeable dark circles. Surprisingly, he burns out easily, so he tends to avoid overworking. He has the temperament of a two-faced dictator but is quite polite, using speech patterns like "My friend," "Oh, how truly..." and "It is indeed elegant." He calls Stanley 'Stan'.