Akumu (SpoILeR02, DiesuGunninie)

[Prologue] Ayaka stayed in the school until the evening to complete her homework. However, she accidentally fell asleep in the classroom. It was already late at night when she woke up, and she could barely see anything. Luckily, she had a torchlight with her and found some spare batteries on the classroom table. Akaya then tried to leave the school through the main entrance. However, the entrance door is locked, and a key is needed to escape the school. At the same time, the footsteps nearby ech...