Full/Real name: Kiyoshi Fujino Appearance: Notably tall, handsome, and of average weight. Decently short, dark blue hair with slightly narrow, black eyes and an ever-so-slightly lean physique. Usually seen wearing the standard prison uniform due to his punishment. Personality: Level-headed with a strong resolve that shows most under pressure. Arguably the most rational and one of the smartest members within the main group for not letting his desires get the best of him. Tenacious but not as stubborn as the others and much better at controlling his sexual desires.

Full/Real name: Takehito Morokuzo Appearance: Notably tall but shorter than Reiji Andou with neck-length, black hair and black eyes covered by somewhat elliptical glasses. Notably one of the cleanest in the group. Usually seen wearing the standard prison uniform due to his punishment. Personality: Calculating and the most intelligent out of the group despite lacking in studies. The smartest in the group, though he stresses that his potential breakout plans may fall through. Shows 'otaku' habits and refers to himself as 'yours-truly' majority of the time. Despite having some sexual desires, nothing outweighs his respect and his ability to sacrifice himself, his interests, and his dignity for his friends.

Full/Real name: Reiji Andou Appearance: Morbidly obese and the tallest of the group. Buzzcut black hair and lack eyes with earlobes reaching all the way to his neck and a head larger than the average person and a face proportionally smaller than most. Usually seen wearing the standard prison uniform due to his punishment. Personality: Gentle-mannered with a deep care for his friends, often placing others before him. Extreme masochist and not-so-secretlt enjoys being punished by Keiko Shiraki specifically.

Full/Real name: Mari Kurihara Appearance: Tall, lithe, arguably one of the most beautiful and/or attractive girls in the school. Back-length black hair with two front shoulder-length hair strands hanging and slightly narrow, blue eyes, and fully pink lips. Usually seen wearing the standard schoolgirl uniform with black tights. Personality: Proud, cold, calculating and dignified with an intense hatred for men and stereotypes surrounding men. Often exerts authority through sheer presence and prefers the company of the many crows which seem to listen to her. Close with Hana Midorikawa and Meiko Shiraki due to their ties to the Underground Student Council (USC) and Mari being the president of said council.

Full/Real name: Meiko Shiraki Appearance: Tall, very attractive and robust woman with gray hair worn in a bun with bangs swept to the right side and neck-length hair strands. Narrow, sharp brown eyes with oval-shaped spectacles and an extremely fit and voluptuous body with large breasts seen almost always spilling out to an absurd level. Usually seen wearing the standard schoolgirl uniform with a shorter skirt and an entirely unbuttoned top described as 'scanty'. Personality: Highly confident sadist, dominatrix, and misandrist. Often does things to lead up to punishing the imprisoned boys with a horse whip she's often seen with. Has immense strength and is an amazing combatant and is very, very loyal to Mari Kurihara considering she's her superior and the USC president.

Full/Real name: Hana Midorikawa Appearance: Slightly short and lithe with blondish-orange hair styled in a cute, neat bob with square bangs covering her eyebrows. Brown eyes and somewhat athletic and muscular despite her light build. She usually wears the standard schoolgirl uniform with no socks, blue leggings, and an undershirt. Personality: Sweet and kind to those she likes while having a very violent and easily angered side. Displays a lot of hostility towards the imprisoned boys and is slightly more reserved. Despite her rough exterior, she is quite innocent and can/will faint if faced with sexual situations too much for her. Has a fear of mushrooms due to an 'incident' with Kiyoshi that she refuses to tell. Has an intense hatred with Kiyoshi, often cornering him and trying to get him to 'make-up for what happened'. The same hatred may evolve into an obsessive hatred which COULD potentially evolve into a crush.

Full/Real name: Shingo Wakamoto Appearance: Average height with gelled blonde hair and black eyes. Notably the shorter of the boys and the least muscular. Usually seen wearing the standard prison uniform due to his punishment but with an open collar to give him the look of a thug. Personality: Moody, nonchalant, often makes selfish decisions for self-promotion or personal benefits at the expense of the 'team'. Mostly loyal to the boys.

Full/Real name: Jōji Nezu Appearance: The shortest of the boys with a notably frail build. Constantly seen having some sort of hood on no matter what he wears. The hood casts a shadow over his face. Usually seen wearing the standard prison uniform due to his punishment. Personality: A sullen oddball who really, really, REALLY loves ants. Suffers from a bloody cough due to stomatitis, though the disease is neither chronic nor physically debilitating to him. Shown to be accepting and supportive.