After receiving a letter from her brother about strange events happening in his town, Tanya, along with her apprentice Riru, travel to Cain village to investigate.

Something strange is happening in Cain village. In just one night, a large forest grew along the road to the town. Worse yet, vicious monsters are seen roaming the forest...

Concerned about what travelers have been telling him, the innkeeper Luis decides to contact his adventurer sister, Tanya, asking her for her help.

After receiving his letter, Tanya and her apprentice Riru, head to the village to investigate.