Mark and Haechan are mortal enemies, Haechan is the student council at his school, while Mark is a naughty student and often skips class, one day Mark skipped class in the library, he and Jeno, Jaehyun, Jaemin, was skipping class, all four of them were smoking, And talk about adult things. Suddenly there was the sound of footsteps, Mark and his friends fell silent, That was Haechan who was on patrol to check whether anyone was truant or not.