Built by one person and a fleet.

Rensei (錬成) is not a word you hear in everyday Japanese. It belongs to a formal register, the language of craft, martial arts, and serious skill-building. It carries the idea that capability is the product of sustained, deliberate effort, a process you keep practicing.

The kanji read "to forge, temper, refine." Mark grew up around the glow of molten steel at his father's mill, where raw iron was tempered into structural metal under heat and pressure. The anvil-crucible mark is that inheritance: the tool work is shaped against, and the vessel that holds raw material at working temperature. Rensei takes raw agent capability and refines it until it holds under production load.

Donmai (どんまい) sits in the opposite register. The hiragana spelling, the casual phonetic script, signals something approachable and forgiving. Donmai is the thing a teammate says after a mistake on the field: don't worry about it, keep going.

Rensei is the platform. Donmai (どんまい) is the runtime under it, open source and named for its own temperament.