Three sisters, while playing in the forest
A huge, never-before-seen "train"-like thing actually appeared among the dense trees.
Full of curiosity, they climbed onto the train secretly.
In a blink of an eye, they came to a European-style building.
What they were wearing was no longer ordinary clothes, but a strange black uniform.
In his hand is an ancient admission notice.
Looking around, there are only dense trees.
They have strange abilities.
Gradually, they solved mysteries one after another
But what followed was a fact that they could never have imagined.
Conception: