One morning, Nagase witnesses the moment his classmate, Tsubasa Amamiya, jumps in front of the oncoming train. He starts thinking about why she'd choose to die but arrives at no answer. Seeing this his friend Fukai hands him a capsule which he claims is a miniature time machine. Nagase, half-in-doubt, takes the capsule and wakes up 2 weeks in the past. He then meets Amamiya on the rooftop under the rain...

First Prize winner of Kodansha Ranobe Bunko's 6th Rookie of the Year award​.