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.
Mountains of ultramarine and verdigris cradle a valley brimming with white mist.
Cup your hands at the cliff's edge and shout “Yahoo!”—two spins later, the valley answers back.
I. The V-Shaped Valley in the Mist
High in the Japanese mountains, a narrow trail winds out onto a rocky cliff overlooking a deep gorge. The board itself takes the V-shaped profile of that canyon—tall cliffs of four rows on either flank dropping down to a two-row valley floor—strung with a swaying rope bridge, a cosy mountain hut, ancient misty pines, and a clear rock spring.
Along the mossy path lie smooth river pebbles, cushions of green moss, drifting clouds, and a bright copper pheasant. Standing at the rim of the gorge, no hiker can resist cupping both hands to their mouth and calling a cheerful Yahoo across the mist-filled ravine.
II. The Spirit Who Mimics the Call
According to Japanese mountain folklore, the echo that answers a traveller in the hills belongs to the yamabiko, a small furry mountain spirit perched on a rocky ledge across the ravine. Whenever a voice rings out through the mist, the yamabiko cocks its ear and playfully tosses the exact sound back across the chasm.
In the base game, whenever the wild yamabiko joins a winning way on the middle or right reels, the friendly spirit mimics the call immediately and multiplies that way's payout on the very same spin, sending the voice straight back before the mist can swallow it.
III. Delayed Echoes Bouncing Off the Cliffs
Let enough Yahoo calls ring out across the board and the hike enters the Valley of the Yamabiko. Inside the free spins, no winning shout ever fades after a single pay: two spins later the win returns as a full echo, and every two spins after that it bounces off the opposite cliff wall again, growing softer and more distant with each rebound.
Even when the final spin of the bonus is reached, any echoes and wall bounces still travelling between the canyon cliffs are settled in full at once before the round closes, ensuring that not a single shout into the valley is ever lost to the wind.
IV. When the Whole Canyon Resonates
Because each winning spin sends several delayed echoes down the timeline, waves from earlier spins soon begin to converge. When enough echoes return on the very same spin, they trigger a booming Big Echo that parts the valley mist and multiplies that spin's fresh win—which then sends out echoes of its own!
Across the cleared ravine, the traveller on the cliff and the furry yamabiko on its ledge wave to one another in the mountain sun. This folklore of canyon and echo is the game's theme rather than a promise: every spin's outcome is decided solely by the server's random number generator.