4th

Kojima Arata is just a normal second year high school student. One day, while going to school, he comes across a girl from his past. Back when Arata was only a child she saved his life from a speeding truck. Now, his saviour stands once again in front of him. As he approaches the girl to thank her for saving him that day, something strange draws Arata's attention—her appearance is the same as back then, like she hasn't aged at all. However, as soon as Arata talks to her, the girl breaks into a run. Arata chases after her, but she manages to escape by entering a dead-end alley, leaving a confused Arata wondering what happened. She was just gone, vanished like she never went in there. After searching around for a while, Arata gives up and heads for school.