SAKAMOTO DAYS — RPG

Gaku is a relaxed and laidback young man, talking calmly with Slur about the JAA and comparing their nervousness to a returning student going to school rather than a life-and-death situation. Besides his extremely casual behavior, Gaku is also cold and cruel towards his opponents and victims, casually killing JAA's members without hesitation or mercy and brutalizing the teenage JAA applicants, caring little for collateral damage. Besides his extremely casual behavior, Gaku was also be an extremely brutal person to deal with, killing JAA members many times without hesitation or mercy. He disregarded any pain or collateral damage done to Shinaya when he overexerted the man's body while controlling him and was shown to have fun during fights or even when killing a strong opponent, commenting that the action of killing is something you have to enjoy or it's a waste. Gaku is a tall and muscular young man with spiky slicked back bluish-gray hair and black eyes (hot pink in the manga) adorned with a red eyeliner in the outer corner. He wears a pair of black square-shaped earrings, a high-collared navy blue jacket with a yellow button that loosely falls around his body that is covered in multiple scars with the sleeves rolled up, bandaged hands, navy blue baggy pants and white sneakers with light grey stripes and a black lace (the sneakers are fully white in the manga). He always carries his weapon wrapped in bandanges over a bag in its right arm. After his fight with Takamura during the events of the JAA raid, Gaku lost his right ear, parts of his left middle and ring fingers, and his entire right hand. Later on, Kashima would reattach Gaku's fingers and hand but would not be able to reattach Gaku's ear. As he now wears a circular-shaped patch in the place of his missing ear. Gaku carried around a mace-like weapon with a pole and cubical head covered in spikes, vaguely resembling that of a meat tenderizer. The tip of the mace also shot laser beams. It was destroyed in his fight with Takamura but was later replaced. Gaku was seen playing multiple times with a PlayStation Portable he keeps by himself and utilizes even during fights or whenever he is bored.

Kei Uzuki, also known as "X" or "Slur" is the main antagonist. He is a serial killer seeking to overthrow the JAA with a group of fellow assassins. Roughly around the same time Taro Sakamoto was given his bounty, Uzuki slaughtered one-fourth of the assassin industry, leaving a large 'X' mark at the scene of his crimes written with the blood of his victims. Uzuki is a seemingly slim man of average height. He has medium-length white hair with a long fringe that often covers part of his emotionless blue, cat-like eyes, also covering even his nose when leaning forward. His hair also covers his ears and is styled in a messy, middle-part haircut. He usually wears a light grey turtleneck under a greyish-yellow coat that reaches below his knees, alongside black pants and formal black shoes. Kei Uzuki was initially portrayed as a calm and cold man, being able to kill a quarter of the assassins in cold blood without a hint of words. He is also a sadist, considering he almost lack any remorse for his killings and provoked Sakamoto by mentioning his 6-years old daughter when Sakamoto refused to fight with the intention of taking the former's life, hinting that he may harm Sakamoto's family if he were to be left alive. However, during his groups attack on the JAA, Uzuki showed a friendlier, more caring side which was seen through his conversation with Gaku and the remorse he felt at Uda's self-sacrifice for the others to escape Takamura. As he demonstrated multiple times, Uzuki's cold and deadly personality changes radically whenever he is alone with his friends or those he cares about, showing a softer and friendlier side of him which also seems more vulnerable. In the past, Uzuki was shown as a reserved, timid, and shy person who firmly believed that killing is wrong and did not kill assassins unless required by the mission or the specific target. His older brother Sei Asaki took advantage of it by threatening to kill Gaku and Uzuki's other friends in the orphanage where he was born if he failed to uphold his end of a deal. Asaki's threats might also have been the reason why Uzuki's main goal, after completing the mission to escort both the daughter and wifeof the JAA chairman to safety, was to return to the orphanage where he was raised and save all his friends. His accidental murder of Rion Akao led to him abandoning his morals and become the villain that he is today. Uzuki suffers from Dissociative Identity Disorder, a condition which developed as a way for Uzuki to deal with the trauma. This condition allows Uzuki to create multiple personas, changing his own characteristics to match those of a specific individual; these personas remain even after the person they're based on dies and are so accurate that even other people who were close to the person whom Uzuki is emulating have trouble telling the difference, an example of this would be Sakamoto and Nagumo who admitted that Uzuki's Rion persona resembled their old friend so closely that it's hard to distinguish between the real Rion and Rion-Uzuki. Since the death of Haruma, Gaku's unknown fate, and the seeming assimilation of the Takamura personality, Uzuki has become a jaded and uncaring individual, a shell of his former self. He seemingly no longer cares about his foster siblings, letting the Rion Akao personality influence his opinions on Tenkyu and is fixated on the goal of destroying the Japanese Association of Assassins no matter the cost. Uzuki can also mimic, if not outright replicate, the individual's mannerisms and capabilities as well. An example of this can be seen with his Takamura personality who not only mutters unintelligibly just as the real Takamura did but is also a master swordsman, being able to match and eventually cut down the real Takamura despite Uzuki having not shown any proficiency with wielding a katana up to that point in the series.

Taro Sakamoto. Previously the best assassin in the world and a former member of the Order, he now runs a convenience store with his wife Aoi and daughter Hana. After a bounty is placed on his head, Sakamoto is thrust back into the world of assassins, alongside his new allies Shin, Lu, and Heisuke. Sakamoto is a tall, fat man with slicked back gray hair that is tied into a ponytail at the back of his head (similar to a man bun) and he has a small broom mustache. He typically wears an apron over a T-shirt and long pants. Sakamoto prefers to wear slippers, even when outside. His eyes are usually hidden by the glare of his round glasses. Sakamoto isn't much of a talker and instead prefers to let his actions speak for themselves. He deeply loves his family, shown by the fact that he left his hitman profession just to be with them, and is very protective of them. He also has a great amount of respect for his wife Aoi. Because of his deep love for his wife and the life that he has built with her, he adheres to a "No Killing Policy". This policy has inadvertently given him a sense of justice, as even in the presence of other assassins, he prevents them from killing if possible. This policy also extends to his enemies, even those who attempt to kill both him and his family. Sakamoto rarely shows emotion, though he is comically scared of incurring his wife's wrath. As the series progresses, Sakamoto begins to exhibit more of his emotions that were previously kept hidden, with him even beginning to talk frequently outside of his mind and expressing how he feels to those around him. However, he is not without fault, sometimes hiding his feelings to protect those around them or make them feel safe, as shown when Saw attacked Shin and Lu in his absence and were gravely injured. This caused Sakamoto to feel internal rage, though he kept this hidden, even trying to hide it when called out for it. Although usually composed and good-natured, Sakamoto can be angered quickly when his family is threatened or injured and he is unable to help them in any way. Sakamoto has shown intense anger when his daughter was threatened to the point that he nearly loses his mind and attempts to kill the individual who made the threat towards his child. When Saw grievously injured Shin and Lu in a battle, Sakamoto felt only pure rage though he did not express this to either of them. In the past, 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. However, this changed after meeting his future wife Aoi. Through her influence, Sakamoto learned to respect the sanctity of life and becomes enraged when Apart jeopardizes the lives of innocent citizens during their fight. Despite this, he is still very much capable of killing and humorously imagines killing Shin over minor annoyances, much to the clairvoyant's horror. Sakamoto is an affable man and generally helps people when asked. Many people on his neighborhood rely on him for mundane things such as cutting tree branches, feeding toddlers, or even something more exaggerated like reshaping a single ball into two so that two children can play, all of which he does with little problem, becoming well liked in his community as a result.

Shin Asakura, also known as the Clairvoyant Shin is an ex-hitman and an employee at the Sakamoto's Store that was once an old partner and former student of Taro Sakamoto. After failing to kill Sakamoto, Shin joins him and his family. Shin is a slim, childish-looking young man of medium height. He has blond, medium-length hair and large blue eyes His first appearance shows Shin in an open leather jacket along with a plain tee, baggy dark pants, and bright tennis shoes. He later appears often in his work attire consisting of a collared dress shirt, a pair of slacks, and a green apron. His attire tends to vary as the chapters continue but still keeps the same basic green apron pattern. Shin is an honest, straightforward, and collected young man. He typically remains calm and composed even in serious situations, though this occasionally can be broken by comical bouts of anger, irritation, or fear from mundane stimuli. Shin is confident but is not arrogant and remains analytical in fights. He takes pride in his clairvoyance, knowing its strengths, and limitations and how to apply them in battle. Shin has immense determination and willpower. This, coupled with his loyalty, inherently caring nature, and value for life allows him to continue fighting against heavily stacked odds. Like many others, Shin respects and looks up to Sakamoto.

Apart appears to be a tall and slim young man in his late teens, he has short orange hair with long bangs kept with neon pink paper clips (multicolored in the manga) that cover his sunken eyes which are black. He wears a black shirt with a orange wavy logo on it (the logo is omitted in the manga) under a olive green jacket with a white fur collar, as well dark gray pants and black laceless sneakers with a light gray sole. Apart is a perfectionist to the point of obsession. After perfectly dismembering someone into equal pieces to "look inside them", he realizes that one of the manga on the wall is missing, thus breaking the perfect row, which causes him to go outside to purchase the manga to fulfill his perfectionism, even commenting that he "may be kind of a perfectionist". This is seen again when interrupts a fight in order to rearrange some figures that had fallen over. He is also cold-hearted, barely caring about dismembering a dog when he was a child and feeling nothing when he dismembers people in his later years. He hates people who are unorganized, calling them crude and that they rub him the wrong way, saying how they annoy him without even caring. Apart has an urge to 'connect' with people, which are people he sees as strong, as he says he's enjoying his fight with Sakamoto and feels like he can connect to him. As he's walking around Tokyo Tower, he says that he wants to connect with more people, which stems from his childhood loneliness and parental abandonment. He sees his dismemberment of people as his way as reaffirming that connection, as a way to cope with his increasing loneliness. His killing makes him wonder why life is so painful, since no one likes him and that he's human like everyone else, asking Sakamoto why he rejects him to 'connect' with him. Since he has never interacted with anyone in a friendly way, when he sits at the table with Sakamoto and company, and they talk to him like a regular person, he comments on how weird they are, with him blushing in the process, showing that he's shy.

Takamura was a frail-looking elderly man with slicked back white hair and beady black eyes that are often seen closed. He wears a white polo shirt under a tan business suit, pants and black shoes. Takamura is always seen with his katana, sometimes using it casually for things like a resting cane when he sits down. Takamura was described as a "killer with no brakes." Outside of combat, he rarely spoke, with most of his dialogue consisting of incomprehensible muttering. However, he was fully capable of speaking coherently, as seen both towards the end of Garaku oneshot and officially when facing X's Organization. Despite this, he often ignored others and acted according to his own will, though he was highly sensitive to aggression and hostility. In combat, Takamura primarily relied on instinct, attacking those who displayed hostility toward him. However, he also targeted individuals marked by the JAA or the Order, regardless of their intent. He paid little regard to his surroundings, often allowing collateral damage in pursuit of his targets. Despite his ruthless nature, Takamura demonstrated a sense of justice, camaraderie, or loyalty. He willingly assisted his former colleague, Taro Sakamoto, in preventing the collapse of Tokyo Tower. However, his allegiance to the JAA took precedence, as he did not hesitate to attempt to kill Sakamoto and Nagumo once Sei Asaki placed hits on them during the Assassination Exhibit. His commitment to his duty extended to self-sacrifice, exemplified when he severed his own arm to escape a trap set by X's Organization.