Shoujo Fujuubun

The protagonist, an author, tells the story of his encounter with a certain young girl ten years ago. During his college days, he once bore witness to a traffic accident wherein an elementary school student was hit by a truck. Strangely, the girl's friend, who was nearby, only went over to check on her after carefully saving the game she'd been playing just before. Soon afterwards, the protagonist found himself captured and confined by this girl.