The gym massacre was an event of Shotgun Boy when the MM-C Variants (except Samshik) began to kill the students and one of the teachers of Yeongchan High school during their retreat, being specific, in the talent show.
Event[]

Three killing a rich student.
At the talent show, things started out normal. However, things took a sudden turn when 05 announced their plans of genocide. She proceeded to kill the announcer, then she killed a few students in the audience. In order to prevent their escape, every present fake employee (01, Three, 04, 07 and one more) surrounded the students and teachers. Three started by asking if any student is rich. A wealthy boy spoke up and explained his family's fortune. Three got delighted to hear that, then he killed the boy and stole his appearance. Another student then begged that they not kill him since he was poor and not intelligent, so the variant, 07, quickly killed him. The variant, 04, then threatened Jayden, but got interrupted when Shinyeong Kang tried to lure in one the variants to kill it. 01 caught on and was about to kill Shinyeong, but then, 05 wanting to kill her instead.
Eventually, they were interrupted when Gyuhwan arrived with a shotgun and proceeded to shoot one of the monsters. The monsters recognized the shotgun. During that moment, Shinyeong escaped and demanded all students try to escape. 04 and 07 tried to kill the boy, only to almost end up getting shot. 01 then demanded to retreat, so 04 made a smokescreen and they could escape.
Aftermath[]
01, Three, 04, 05 and 07 make it to an abandoned shack. However, 05 is sent to deal with the remaining phones while 03 does its own thing.
Director Lee, Jongpil, Seonyeob, Gyuhwan, Shinyeong, Jayden, Ms. Kim, Ms. Ahn and two unnamed students survive by staying in the building.
Yeongshin Cho and Chayeong Park manage to escape together. Chanhyeok Park and Sanggwon Ahn also escape together.
Victims[]
- The announcer.
- PE Teacher.
- Rich Boy.
- The dance team.
- Jiyeong (offscreen).
- Unnamed Variant.
- Various other students.