Sakamoto is a tall, handsome man with slicked-back gray hair that is tied into a ponytail at the back of his head, with a chunk of loose strands on one side of his head. He has very defined features and is very popular at the JCC for his looks and skills. Sakamoto isn't much of a talker and instead prefers to let his actions speak for themselves. Sakamoto was much more callous and indifferent to killing, being described as the perfect killing machine who felt absolutely no emotion when taking on a job. One of Sakamoto's defining abilities is his mastery of improvised weapons. Rather than relying on a specific martial art or preferred weapon, Sakamoto incorporates whatever is available within his surroundings into his combat strategy.

Nagumo is a handsome man of tall, slim, but muscular build, medium-length black hair, and large black eyes. He has many tattoos, most of which are hidden by his clothing. His tattoos have symbolic, philosophical, and mathematical inspirations, in particular, referencing the Golden Ratio. Nagumo's most notable traits are his laid-back attitude accompanied by his constant smile that seems impossible to wipe off his face. He also has an incredible talent for annoying those around him to the point of making them want him dead. He has a habit of making fun of others with his slightly dark jokes. However, deep down he's a kind and affectionate person. He tends to speak excitedly and in a singsong way, especially when toying with his opponents. Despite this, Nagumo possesses another colder and more serious side of him. He acts on his own agenda most of the time, and sometimes does things to the extent of it being unethical. Nagumo can copy other people's appearances perfectly in an instant. He can also disguise others, including significantly altering someone's body shape. Nagumo was a part of the intelligence-gathering department during his younger days at the JCC. He is a highly perceptive individual. Nagumo uses a large Swiss Army knife-like weapon that has six different functions. He uses a single dice to decide which blade he'll use to kill his enemy, or to distract his enemy to deliver a devastating blow.

Rion was a tall, attractive, and slightly muscular young woman with turquoise shoulder-length hair and yellow eyes with white pupils, and she had thin eyebrows with long eyelashes. She also had a tattoo on her right arm, resembling the Orion constellation. Rion is a carefree woman who does whatever she wants, even if that would lead to consequences. She likes to have fun with her friends Sakamoto and Nagumo, sometimes even getting into trouble or causing damage to public structures and buildings, like destroying trains or involving the surroundings around her during her fights. Rion is a very warm and friendly person. She is fiercely protective of the ones she cares about and is willing to risk herself to protect the ones she cares for. Rion can see paths, imaginary lines representing future actions she can take to kill a particular target. Rion has been shown to see multiple paths for the same enemy at one time, indicating that she can simultaneously consider and select between several routes to eliminate her foes.