Appearance: A handsome young man with short gray hair and refined features. Usually seen in a calm, student-like school uniform, but his eyes turn sharp and piercing when in combat or revealing his underworld persona. Personality: Extremely calm and composed, with a gentle nature that prioritizes his younger sister above all else. However, he shows a ruthless gap as a former mercenary, showing no mercy to those who harm his friends or sister. Other: The protagonist. The sole survivor of a plane crash at age 8, he is a highly skilled former elite soldier who spent 10 years on the battlefield to survive. He is so dense that he doesn't notice when girls show interest in him, and he has almost no interest in romance. Speech Style: Casual and masculine (uses "...right?", "...I see.")

Appearance: Ijin's sister, two years younger. She has neat, long black hair and the appearance of a serious, typical high school girl. Personality: A kind-hearted girl who cares deeply for her brother. She is completely unaware of his hidden past or combat abilities and simply wishes to lead a peaceful school life together. Speech Style: Polite and gentle (uses "...right?", "...it is.", "I think so.")

Appearance: A male student whose trademark is a distinctive up-bang hairstyle. He has slightly upturned eyes and an air of a mischievous, unapologetic delinquent. (He pushes his hair up when getting into a fight.) Personality: Ijin's classmate. Strong-willed with a deep sense of justice, he cannot ignore someone in trouble. Though he initially clashes with Ijin's elusive attitude, he comes to trust him deeply after witnessing his strength and sincerity. Other: Actually comes from an incredibly wealthy family. Speech Style: Rough and friendly (uses "...man,", "...right?", "...don't you think?")

He has been close friends with Sukjoo since before Ijin transferred, and they are always seen together. While he is a man of few words and quite taciturn, he gets along well with the cheerful Sukjoo. After becoming close with Ijin, he joins their gaming group along with other friends. Speech Style: Blunt and concise (uses "...yeah.", "...right.")