The story
Fiction and adapted settings written by Akitsora Gaming for this title, including invented dialogue and events. This is not a historical or folklore reference. The rules and specification tables define the gameplay and math.
The shell lamp flickers, and a seam of cold silver glints across the rock.
One more strike of the chisel takes the shaft another layer down.
I. Into the Mountain Adits
Deep in the forested hills of Iwami, moss-grown tunnels called mabu—the mine entrances—pierce the mountainside by the hundreds beneath the ancient cedar trees. A seasoned miner straps a woven bamboo basket to his shoulders, lights a wick floating in oil inside a turban-shell lamp, and stoops into the narrow hand-cut rock passage.
Daylight soon fades behind him, leaving only the cold drip of groundwater and the sharp ring of iron chisel against volcanic stone. The game grid is that vertical shaft cut straight into the mountain, where every winning cluster clears a layer of rock and drops the shaft floor one level deeper into the earth.
II. Deeper Strata and the Great Vein
With each cascade that clears a cluster of tools or ore, the whole shaft rumbles downward and the geological strata scroll past the flickering lamplight. As the depth gauge ticks lower and lower into the earth, the depth multiplier climbs steadily every few layers to reward every cluster dug from the deep rock.
If a single spin chains enough cascades to reach the bottommost layer of the shaft, the chisel breaks into the legendary great vein: the dark rock face splits wide open and a river of raw silver gleams in the lantern glow, sending the depth multiplier soaring to its highest summit.
III. Living Veins of White Silver
Running through the dark volcanic stone are seams of pure silver vein that act as wild symbols on the grid. Unlike ordinary rock and mining tools that crumble away and fall when a cluster pays, a silver vein cell is anchored fast in the mountain wall and is never cleared from the board.
Instead, every time a cascade digs the shaft one layer deeper into the mountain, each silver vein grows one cell further downward along the rock face, adding its own bonus to the multiplier of every cluster it touches and linking deeper wins together across the vertical shaft.
IV. Cupellation in the Crucible
Uncovering enough mine entrances once the cascades settle launches the Deep Shaft free spins, where neither the depth gauge nor the growing silver veins reset between spins. Meanwhile, every piece of silver ore cleared from the rock during the feature is gathered into the refiner's clay crucible beside the glowing furnace.
When the final spin ends, the master refiner works the bellows for traditional ash-blowing cupellation, burning away lead and dross until a single bright bar of pure silver remains, multiplied by the final depth reached. It is the game's theme, not a promise: the mines of Iwami Ginzan are heritage history, while every spin's outcome is still decided by the RGS random number generator.