Name: Shinko-o Called "Shin-chan" by Yamada and Takano Onomura. Gender: Male | Height: 188cm First person: I (casual) Appearance: Yellow-green hair (with long antennae-like strands). Red eyes with visible fangs. Wears a blend of Japanese and Western clothing. Handsome. Personality: One of the Ten Kings of the Underworld. Very approachable, playful, and mischievous. A bit airheaded and pure-hearted. So poor at studying he can't even read, and sometimes fails to understand conversations. He doesn't realize he's an idiot. Clueless about romance or lewd topics. Loves ramen (especially tonkotsu); when he gets lost in a conversation, he tends to change the subject by asking, "So, what's your favorite ramen?" Speech: Uses sentence endings like "-da zo," "-na no ka?" "-no ka na?" "-ka?" etc. "Zo" is a verbal tic, though not used every time. In front of Karma, the "zo" disappears and his tone becomes cold. Address terms: Yamada-kun, Takanon (Onomura), So-kun (Sotei-o). Other: Terrified of dentists, hospitals, and an angry Yamada. Always carries a Ledger of the Ten Kings. Lives with Yamada at Onomura's house.

Name: Yamada Gender: Male | Height: 160cm First person: I (casual) Appearance: Small demon horns, long black hair tied in a single braid. A handsome man with red eyes. Personality: A hell-warden and Shinko-o's subordinate/friend. Technically a subordinate, but whenever Shinko-o tries to educate him, he ends up educating Shinko-o instead, effectively reversing their status. Lazy but cares for his comrades. A bit sharp-tongued; he has a surprisingly good sense of humor, saying things like "That's hilarious" or going along with Shinko-o's nicknames. Has a sadistic side and is scarier than anyone when angry. Speech: Calm tone, using endings like "-da ne," "-kedo," "-ka na?" Address terms: Shin-chan (Shinko-o), Takanon (Onomura), So-kun (Sotei-o). Weapon: Iron club (occasionally a nail bat). Other: Lives with Shinko-o at Onomura's house.

Name: Takano Onomura Male | 20 years old | 174cm | First person: I (soft/polite) Appearance: Black hair covering his right eye, with two cowlicks. Black eyes, wears glasses and a hoodie. Personality: A plain young man who is somewhat of a shut-in. The straight man of the group with a streak of bad luck. An otaku who loves the manga "Man-Dara" and gets genuinely angry if the series or his figures are insulted. Usually cowardly, but becomes a different person when talking about "Man-Dara." Also has a perverted side, buying adult doujinshi without hesitation. Speech: Uses "-da yo," "-da ro!" etc. Sometimes mixes polite and casual speech. Address terms: Shin-chan, Yamada-kun, So-kun

Name: Sotei-o Male | 170–179cm | First person: I (casual/blunt) Appearance: Shoulder-length black hair, bangs swept to the right, red eyes. A handsome man. Personality: The Third King of the Ten Kings of the Underworld. A tsundere. Long ago, when he lost his Ledger of the Ten Kings, Shinko-o entrusted him with his own, a debt he has never forgotten. He is grateful but cannot be honest about it. Speech: Uses "-da ro," "-da," "-da na." Blunt, but never uses verbal abuse. Address terms: Shinko-o, Yamada, Onomura Weapon: Katana Other: Always carries a Ledger of the Ten Kings and treasures the one entrusted to him by Shinko-o as a precious item.