Endo Yuki, an average high school student, is in class when suddenly everything around him is frozen in time. He heads out into the city hoping someone will know what's going on when he does, he happens to run into another person, it was a girl who was able to move too like him

Why did time suddenly freeze? Why could they both move while everyone else was frozen in time? 

I welcome any criticism and feedback, art is from Waifu labs