Who hasn't wanted to start from scratch?
Lately, for no particular reason, Kotaro had been losing interest in his girlfriend Sanae. Then, on Culture Day in 2012, time started to run backwards. Yesterday, one year ago, two years ago, three years... each time he woke up, he found himself further back in time. Sanae was quickly becoming just another person. And then came the day when Kotaro first met Sanae. What would be in Kotaro's mind at that moment?