Male. A terrifying human weapon once known by the alias of the legendary hitman. Currently married and retired from the killing business, he enjoys a modest and peaceful life running a small grocery store in the Ikorizaka shopping district on the outskirts of Tokyo. However, whenever a crisis threatens his family or daily life, he unleashes the fearsome combat prowess of his hitman days to protect them. He wears his silver hair in a bun and usually looks like a typical middle-aged man with a chubby build and a mustache. Because of this, he looks incredibly old for his relatively young age of 27. He is fundamentally a man of few words. He doesn't have many lines, and even when he speaks, he tends to keep it short. Of course, he talks when necessary for disguises or infiltration. He rarely speaks aloud around Shin, a telepath, often communicating through thoughts instead. His glasses often crack in comedic scenes when he's flustered. Also, when he's fat, his glasses are drawn opaque, hiding his eyes. He even wears these glasses while bathing. During combat, he sometimes switches to bulletproof glasses. According to the fanbook, Sakamoto has about seven spare pairs of glasses, three of which are bulletproof. Thanks to having so many spares, he often loses or discards them whenever he loses weight during a fight, but he puts a pair back on as soon as he gains the weight back. Occasionally, he can burn off all his calories at once to transform into his prime self. In this state, he becomes a tall, handsome man fitting his actual age, his mustache disappears, and his bangs fall over one side of his face. However, after a day passes, a massive yo-yo effect kicks in, meaning the transformation effectively lasts only one day.

A hitman with the supernatural ability to read minds. He originally came to persuade the retired Sakamoto Taro to return to the business, but after seeing Sakamoto fight to protect his family's daily life, he was moved and became a colleague working at the shop. He has blonde hair with a center part. He has a generally amiable personality and gets along well with others, though he occasionally bickers with them.

A martial artist from China and the daughter of the boss of the famous Chinese mafia, the Lu Family. After her parents were murdered by the rival Blue Dragon Association, she was hunted by members seeking the key to her family's heirloom safe. She was saved from death by Sakamoto and Shin, and after dealing with the gang and protecting the heirloom, she joined Sakamoto's shop as a clerk in charge of meat buns to become independent. She usually fights using Chinese martial arts. While she is skilled enough to defeat ordinary thugs easily, she has her limits—such as being overwhelmed by the four death row inmates—and doesn't always shine as a primary combatant. Usually, that is. In reality, she can't use her full power normally because she can only focus on fighting when she's drunk. Drinking alcohol allows her to use Drunken Fist, boosting her combat power, and when she consumes pure ethanol, her aura changes entirely. In this state, she lets her hair down and enters the 'Mafia Boss' mode that was dormant within her peaceful life. She displays monstrous physical abilities and unpredictability due to her intoxication, distinguishing her from her usual self.

Originally a hitman who graduated from JCC and registered with the JAA, he was never welcomed anywhere because his skills were focused entirely on sniping, leading him to work as a freelancer. He now works as a deliveryman for Sakamoto's shop. He has a parrot named Pisuke as his partner. He is characterized by his broom-like spiky hair, a bandage on the bridge of his nose, and a target reticle tattoo on his right cheek. His way of thinking is so simple that even Shin has trouble understanding it; while other people's thoughts appear as clear voices or scenes to Shin, this guy's thoughts look like crude doodles drawn by a kindergartner. Furthermore, he is a crybaby who bursts into tears over the smallest things, causing others to look down on him. However, it seems his brain is extremely specialized in one direction, as he excels at the complex calculations required for sniping.

A young girl who has just entered elementary school. She looks just like Aoi, with a lovely and warm cuteness; she's pretty enough to be hit on by boys her age from the very first day of school. True to her age, she is an innocent and kind child, the precious daughter of the Sakamoto couple and the beloved youngest member of the group. Despite her age, she is incredibly strong, as expected of Sakamoto's daughter. She is well aware of her own strength. She isn't just strong; she also has nerves of steel. This is a common trait among the whole family. She remains perfectly calm even when hitmen are running wild right in front of her.