Since her mother passed away, Mizuki has lived with her father. Recently, due to her father's work, they moved closer to her grandfather's house, and the three of them have been eating dinner together more and more. One day, Mizuki ends up staying at her grandfather's house because her father can't come home from work. Her grandfather then invites her into the storehouse, saying, "Why don't you take a look at my work while you're here?" Mizuki innocently enters the storehouse...