Shibata moved to the village after the family accident. He lives with his sister, Shiori, in their late grandfather's house. His life goes on normally until the appearance of a mysterious girl piques his curiosity. Unbeknownst to him, he becomes connected to another world and gets involved in significant events within it.

Nana fell into the 'rabbit hole' and took on many tasks as a form of responsibility, but there were more valuable lessons she learned inside.