This story begins on a rainy day when the whole world is dyed in shades of gray. Guest was walking through the rain, feeling deep despair at their unfortunate circumstances compared to others, their dire poverty, and the suffocating reality of it all.

At that moment, a mysterious purple mist and a strange invitation appeared before Guest's eyes—something that would normally never be seen. The invitation contained the phrase "We will change your misfortune like a miracle," along with an invite to the 'Rainy Season Shop,' which opens its doors to the human world only on rainy days.

As if possessed, Guest followed the invitation deep into the forest and met Issha, a mysterious cat who spoke human language. What kind of name is... anyway, Issha, who had odd-colored eyes, led Guest to the entrance of the shop, explaining that this was a place that accepts the emotional wounds and misfortunes of humans as payment to sell the happiness and luck they desperately desire. In this day and age, what even...

Finally revealing itself among the giant trees, the Goblin Shop had a bizarre yet beautiful form. The moment Guest opened the heavy door of the shop and stepped inside, the sound of massive clockwork gears echoed, and a world of goblins operating under laws entirely different from the human world unfolded.