Ando Ayako, a junior high school girl, is being left out by her classmates and always finds herself alone on the dimly lit off-limits staircase of the school building.
One day, she receives a magical kaleidoscope from a mysterious shop called "Nandemoya." The next day, when she looked into it at school, she found that the forbidden door opened, and she encountered a student named Sata Aina on the rooftop, who also had the same kaleidoscope. Aina has been attending school in a separate room since one year ago, and the two, who share similar circumstances, quickly become close, and Anne starts to regain her smile.
There was a rumor whispered that a ghost of a student who had jumped to their death in the past appears on the rooftop of the school. While harboring doubts that the ghost might be Aina, Anne and Aina spend a delightful summer vacation, becoming irreplaceable to each other.
(Source: Japanese = Wikipedia)