Chise is the main female character of Saikano. She's is a shy, clumsy girl with very little self-esteem and has poor grades in everything except for World History. She was constantly hospitalized in Tokyo during her elementary years, and thus, has very few friends (except for Akemi). She starts dating Shuji, with Akemis help, and tries to make her relationship work with him despite his apparently aloof personality. However, Chise is very inexperienced and does not know much about relationships, to the point she reads shoujo manga for advice. She was turned into the ultimate weapon against her will, and the series revolves around her and her fading humanity. Chise tries to come to terms with her new weapon body while also trying to convince herself she is still human.
As her condition worsens, she is convinced she is nothing more than a weapon. She believes that there is nothing human about her anymore since she thinks all she can is destroy. She claims that weapons were made to kill and destroy. Her boyfriend Shuji, however, is able to help her overcome this belief on the basis that she is able to protect something that she loves, rather than destroy it, and that love is a feeling only a human can experience. Chise's love for Shuji allows her to realize what she truly is, and it also allows her to break free of the body that has been taken over by the weapon that it was turned into.