All the Ghosts Under the Ghost School Were Eaten by Me!

After graduation and without a job, I was invited by the principal of No. 5 Middle School to become a teacher. At first I thought it was just ordinary teaching, but I didn't expect that the weird things had just begun! The weird lights in Building 3, the fifth floor of the dormitory that should not be there, the two principals in the room, and the coffin buried in the grass... Is this a ghost school? I have no idea. But I know they are ghosts...