Proposal Daisakusen

Ken Iwase is on a wedding ceremony of his best friend since being children Rei Yoshida, but unfortunately for him, he is not the groom, but Tetsuya Tada, who was a student teacher at her high school and later taught at her college. Ken feels sorry for himself, because he was never able to tell her about his real feelings for Rei, has to give a speech about the good old times with Rei and is starting to get drunk afterwards at the party. When he stares at an old picture in a presentation a man appears, sending him back to the time the picture was taken to correct the mistakes he made, changing the past and of course the picture. A photo can only be changed once, but at the party are a lot of photos he wants to go back to. This way he is trying to become the groom. Will his small changes be enough to do it?