The 10

Lore & Background

In the assassin underworld of Sakamoto Days, skill is currency and reputation is law. The 10 sit at the very top of that economy: ten individuals whose combined lethality, tactical brilliance, and sheer will make them untouchable by any single opponent. They are not a corporation with a boardroom or a criminal syndicate with a territory; they are a peerage of killers, bound together by mutual recognition of one another's caliber. Membership is not granted by a council—it is earned through a level of mastery that few in a generation can match, and the roster shifts only when someone falls or is surpassed.

The group's internal culture is one of quiet, almost aristocratic rivalry. Members do not issue orders to one another as a hierarchy would; instead, they challenge, test, and push each other to new heights of violence and precision. This makes them simultaneously the most dangerous collective in the world and the most unpredictable, because any one of them can turn on the others without warning. Their contracts, when they take them, are not for money but for principle, pride, or the sheer enjoyment of the act—details that make them far more terrifying than any organized crime cell.

Sakamoto's place in this mythology is singular. Before his retirement, he was the one name that even The 10 acknowledged as above them—the living standard against which they measured their own excellence. His departure from active duty left a void that the group has never truly filled, and the story's central tension is partly about what happens when that void is probed, challenged, or exploited by those who believe they can now claim the throne he left behind.

In Their Own Story

The rain had turned the convenience store's glass front into a running mirror. Ganta wiped the same shelf for the third time, the fluorescent hum the only sound in the empty aisle. Outside, a black sedan idled at the curb, engine off, headlights off. The driver's silhouette was still. Patient. The kind of stillness that meant a name had been spoken in a room Ganta would never enter. He set the bottle of tea back on the shelf, aligned it with its neighbor, and watched the sedan's reflection in the glass. Somewhere above the city, in a room with no windows and no clocks, one of the ten was deciding whether to make a move tonight. Ganta straightened his apron. He had a shift to finish. The world could wait until closing.

Reader's Guide

Purpose and purpose statement: The 10 exist as the recognized apex of the assassin world. Their stated or implied goal is not territorial control or profit in the conventional sense; it is the pursuit and maintenance of supreme lethality. Each member is a walking standard of what a killer can become, and the group collectively represents the ceiling of that discipline.

Leadership: The 10 do not operate under a single commanding officer in the way a military unit would. Authority is situational and earned through demonstrated superiority. Decisions that affect the group as a whole tend to be reached through mutual assent or, failing that, through a direct contest of skill. This makes the group agile but also prone to fracture when egos collide.

Membership: Exactly ten individuals at any given time. Entry is not a recruitment process; it is a recognition event. A killer who demonstrates a level of mastery that the existing ten cannot ignore effectively inserts themselves into the circle, displacing the weakest or most stagnant member. The roster is small, closed, and fiercely guarded.

Resources: The 10 do not rely on a shared treasury or armory. Each member is self-sufficient, carrying their own methods, tools, and networks. Their collective power comes from the sum of ten individually complete operators, not from institutional backing.

Relationship to Sakamoto: Sakamoto was the one figure who stood above the ten—the benchmark. His retirement removed that benchmark, and the story's escalation is driven in part by the group's (and the wider underworld's) reaction to that absence. The 10's ambitions, rivalries, and willingness to test the limits of the world Sakamoto once held in check directly shape the central conflict, raising the stakes from personal vendettas to a reordering of the entire assassin hierarchy.

Did You Know?

• The 10's name literally encodes its membership size: exactly ten individuals, no more, no less. The roster is a fixed slot, not an open-ended organization.
• Sakamoto's pre-retirement status placed him above even this elite tier, making him the singular reference point against which all ten measured their own skill.
• The group's internal dynamic is one of peer rivalry rather than top-down command, meaning any member can challenge or turn on another without institutional sanction.
• Their contracts and motivations are portrayed as deeply personal—pride, principle, or the aesthetic pursuit of perfection in killing—rather than purely financial, which sets them apart from ordinary criminal organization