; : (Drama CD) : The protagonist in the game and the
Various Heroines manga. Kōichi is in class 2A and is the older brother of Nana. In the game his given name and surname can be customized by the player. In the anime his character was split in two characters - Kouichi Sanada (who received the original protagonist's looks and given name) and Kazuki Aihara (who received the original protagonist's soccer skills, surname, Nana as little sister, and voice actor from the Drama CD). ;: : The main heroine in the original Visual Novel. Kouichi's classmate, who works in school library. In anime she is Kouichi's love interest. She has always been shy but the help of Mao and the others, she becomes more outgoing. She also has feelings for Kouichi and they begin to date. However, she realizes that he has feelings for Mao even before he breaks up with her. ;: : The main heroine in the anime. Mao is very active, energetic, and cheerful student in class 3-A. In anime, she lives with Kouichi and his mom after moving back to Japan from Paris, but moves out due to her feelings for Kouichi. Mao's first love interest in the anime is a quiet, tough looking boy named Eiji Kai. At first, they dislike each other, but soon develop feelings and begin to date. The relationship does not last long due to Mao realizing her feelings for Kouichi and she breaks up with Eiji. ;: : A girl from class 2-С (in anime she is in class 2-A with Kouichi and Kazuki), who loves to play soccer. In anime she starts to have feelings for Kazuki after he helps her. Sakino discovers that Eriko and Kazuki are conducting 'experiments' together which angers her, and she wants them to stop the experiments. She soon realizes that Kazuki is in love with Eriko, despite the fact she always pushes him away. Towards the end of the anime, Sakino confesses her feelings to Kazuki, but is turned down. She gives him a kiss as a goodbye to her feelings for him. ;: : An extremely introverted girl from class 2С, who is always cold to others and has an IQ score of 190. She usually spends time alone in the science lab. In anime she starts performing experiments with Kazuki (such as kissing him), who found her hiding place, in order to find out why people fall in love. Gradually she develops feelings for Kazuki and opens up to others. In the last episode, Eriko professes her love to Kazuki and the two kiss. ;: : A wealthy girl from class 2-B, who is proficient in many arts. : In the anime she is in class 2-C with Eriko, and gets recruited into the Movie Research Club. She has had an arranged engagement for most of her life yet has never met the man. ;: : The younger sister of the protagonist (Kazuki in the anime). She carries an accessory depicting a green frog whom she has named Iwao. In the game, her surname changes to match the player customization of the protagonist's surname. ;: : A good friend and classmate of Nana. She is an expert at cooking
udon and has a strong interest of creating new varieties of udon. Like Nana, she also carries an accessory depicting a frog whom she has named Juliet. ;: : A close friend and classmate of the protagonist. He offers love-related advice to the protagonist from time to time. : In the anime, he is the president of the Movie Research Club, and always forces Kouichi and Kazuki into helping him with his films. ;: : A member of the school disciplinary group. She is high strung and the self-appointed head of the school morals enforcement agency. In anime her love interest is Hiiragi. ;: : The school's modern Japanese language teacher and adviser to the swimming club. She is Mao Mizusawa's home room teacher.
Anime-only characters ;: : An anime only character and the first protagonist. Kōichi's first love interest is Yūmi Hoshino, but he gradually develops feelings for his childhood friend, Mao. At the end of the anime, he and Mao become a couple. ;: : An anime only character and the second protagonist, he is Kouichi's classmate and good friend. Kazuki enjoys playing soccer and his love interest is Eriko. Kazuki meets Eriko in a classroom and experienced his first kiss when she suddenly began an 'experiment' with him. Kazuki eventually realizes that he has fallen for Eriko, and chases after her all throughout the anime. The two finally become a couple near the end of the anime. ;: : An anime only character. Mao's classmate, who plays the saxophone and works in a jazz bar. Initially, he does not get along with Mao but gradually opens up to her. He and Mao date for a while but she breaks up with him after she admits her feelings for Kouichi to him. They remain friends. ==Adaptations==