The protagonist, Risa Koizumi is not your average Japanese high school student. Standing 172 centimetres (5 ft 8 in), Risa’s height is well above that of most Japanese girls her age (the average height for a female is 160 cm (5 ft 3 in)) Ironically, her surname means ‘little spring’. She and other characters compare her to a giraffe. Risa can be impulsive and strong-willed at times, and is rarely willing to display her softer side. She had a crush on Suzuki before he started dating Chiharu. In the beginning of the series, Risa is 170 cm (5 ft 7 in) but she gains 2 cm (0.79 in) in height to become 172 cm (5 ft 8 in).
Risa starts developing feelings for Ootani and soon admits to herself that she likes him. She then starts trying to confess. Failing the first time, Nobuko and Nakao try to help, Nobuko often giving Risa advice on what to do. Finally she very directly tells him. She immediately regrets it, and tells Ootani to pretend it never happened, but in spite of herself she tells Ootani once again that she likes him. Ootani responds that he couldn’t see her as a girlfriend yet, so her new goal is to make Ootani regret that and make him like her as well. Eventually they start going out.