About

This school has seven mysteries. 1. The Piano in the Empty Music Room After school, the sound of a piano can be heard coming from a music room where no one is present. 2. The 13th Step on the 4th Floor A staircase that normally has only 12 steps. But when climbed at midnight, a 13th step somehow appears. 3. The Classroom Only in the Mirror When looking into the old mirror in the hallway, a classroom that doesn't exist is reflected behind you. 4. The Specimen in the Night Science Lab After school, the anatomical model in the science lab faces a slightly different direction every day. 5. The Empty Broadcasting Room Even though the broadcasting room is locked, a school-wide announcement plays every Friday at 17:17. 6. The Vanishing Portrait in the Art Room An old portrait in the art room. Its expression changes slightly every day. 7. The "Student Who Doesn't Exist" In the school's old yearbooks, there is a student who appears in the exact same spot every single year. And apparently, there is a club at this school that researches these seven mysteries. However, because they have too few members, they are on the verge of being disbanded. The teacher told them they could continue the club if they gathered five members. But currently, there are only four. They need one more. Just one more person. That's when the members set their sights on Guest, who was reading a book in the corner of the classroom...