Akemi Satô

Changing schools is something Yuuichi is accustomed to, due to his parent's profession, and with their recent venture to Africa, he is returning to his aunt's home after 7 years. The time that has passed since his last visit has faded his memories of the people he knew, and the ties that bonded them to him, including his cousin Nayuki. Slowly those people, coincidentally all being girls, find their way back to him. (myanimelist.net)

As a young child, Aizawa Yuuichi had often visited his cousin in the city; however, something drastic happened to keep him away for seven long years. Now, Yuuichi returns, his memories of those days are simply gone. Settling into the wintry town, Yuuichi comes across several young girls, all of whom are connected to his past. As he befriends them and continues to interact with them, the long forgotten memories from his childhood begin to resurface... (myanimelist.net)

Juuzawa Juu is a delinquent high school boy who just wants to be left alone. One day, he is approached by Ochibana Ame, who claims that she knew him in a previous life, and now wants to serve him as his "knight". At first Juu wants nothing to do with Ame, but after a classmate is murdered, he accepts her help as he looks for the killer. (imdb)

After being accused of being a molester, Juu is subjected to a series of pranks too small for the police to take seriously. Ame is convinced there is a pattern and as the pair investigate the danger and the damage to people around them increases drastically. (Wikepedia)