Kaho started seeing a man standing by the window of a train running in parallel at the same speed for only 12 seconds while traveling from Tokyo to Akihabara by train every morning. However, recently, he hasn't been seen, and Kaho can't help but be worried.
Apparently, Kaho fell in love with him. The three decide to look for the man.
However, the only clue is a picture of Kaho taking a man on the opposite train from inside the train.
