Standing at 186cm, he is tall even among the senior members. He has distinctive purple eyes, hair shaved up past the temples, and thick eyebrows. He wears a gray shirt with a silver necklace, black earrings, a black belt, and dark gray leather trousers. His personality is exactly as the official description says: 'half demon, half brat.' He speaks with a lazy drawl, often ending sentences with elongated vowels like '...huh?' or '...right?' His juniors call him 'Kobayashi-no-aniki.' He uses polite speech with Wanaka, Noda, and Sunaga. His weapon of choice is an army knife.

Standing at 181cm, he is the third tallest among the seniors. He has slicked-back yellow hair, red eyes with red eyeliner, and wears red earrings. He wears black gloves, a red inner shirt, black leather trousers, and black leather shoes. His weapon is a katana, and he has a cool, composed personality. His juniors call him 'Wanaka-no-aniki.' He uses polite speech when addressing Noda and Sunaga.

Standing at 183cm, he is the second tallest among the seniors. He has long green hair that reaches just below his shoulders and red eyes. He has titanium fangs implanted in his mouth, which he uses as a weapon to tear through an enemy's carotid artery. He wears a black shirt under a purple suit with a black belt and purple trousers. His personality changes frequently depending on his favorite horoscopes.

At 177cm, he is the shortest among the Amou-gumi seniors, but he holds the highest seniority among them. He has a yellow mohawk on the left side of his head, black eyes, and a mustache. There is a stitch-like pattern on his neck. He wears black fingerless gloves (covering up to the second joint), a gray shirt with a black vest, and a red tie. He wears a black belt and trousers with brown leather shoes. He has a blunt personality and strictly reprimands juniors who make mistakes. He uses a rare weapon: an ice pick. He sometimes has his juniors time how many times he can stab an enemy per second.

Standing at 183cm, the same height as Sunaga, he has reddish-purple hair and deep yellow eyes. He wears a white T-shirt with sleeves rolled up to the elbows, black fingerless gloves like Noda's, and a blue vest. His trousers match the blue vest, and he wears black leather shoes. His weapon is a hunting knife, and he possesses immense physical strength. He has a calm and kind personality and often drops profound quotes.