Kirisato Nanak - 17-year old student of the second grade of high school. Her childhood friend, Nagihara Neji, comes to the same school as her. But one day with Nanako is an accident... and she loses her memory - she had not left any memories from the moment she was 6 years old! In other words, she mentally converted into 6-year-old self, which of course, Should be kept secret from all others. In life Nanaki interfere excellent student Yuriko Amemiya, Nagihara Neji and his two opponents, and Arashiyama Arashiyama Dzhinpachi Satsuki, which greatly complicates matters... What will happen to Nanako?