Girl #21 Yoshimi Yahagi is a rebellious girl with wavy, long hair and is in a relationship with Yoji Kuramoto (they met while watching a movie). Yoshimi Yahagi is one of the class of third-year students at the fictional Shiroiwa Junior High School. She was a member of the gang headed by Mitsuko Souma, along with Hirono Shimizu. Yoshimi used to regularly steal from and torment her classmates. She often singled out Kaori Minami out of the girls. Yoshimi is described in the novel as one of the more urban girls in Shiroiwa; she never saw a sickle before in her life. Yoshimi was in love with Yoji Kuramoto, her boyfriend. They met at school and started dating when they ran into each other while out shopping. They first slept together on Saturday 18th January. She was arrested several times for theft, and once for blackmail. She dabbled in prostitution, after Mitsuko Souma introduced her to some middle-aged men who were willing to part with their money, but she stopped when she started dating Yoji. In the manga, Mitsuko had allowed Yoshimi to be raped by two men, charging them extra because she was a virgin. With the money she gained, decided to see a movie based on her favorite TV show, Alley Cats. During a tragic scene, she noticed Yoji was sitting next to her, crying. The two recognize each other from class. He tells her that he is a big fan of the actress who plays the main character of the movie. Afterwards, Yoji admits that the reason he likes the actress so much is because she looks like Yoshimi. From then on, the two started dating.
In the novel and manga, Yoshimi is thrilled when she manages to meet up with Yoji, but is shocked when he attacks her. They talk briefly, and Yoji starts to realise that he could not kill Yoshimi because he loves her. Before they could do anything, Mitsuko appears and kills Yoji; in the novel, Mitsuko stabs Yoji's head with her sickle, in the manga, she picks up Yoshimi's gun and shoots him through the head. In the manga, she begins to lose it a little when she tries to reassemble Yoji's brains and reprimands him for his mess. Yoshimi finally notices Mitsuko. Angry at this, Yoshimi threatens Mitsuko, who retaliates and shoots Yoshimi in the eye; Mitsuko wishes to use Yoshimi as a human shield prior to the incident. Masayuki Taguchi, creator of the manga version, did not model his version of Yoshimi after any particular person. Taguchi said that he listened to many women and felt that they had a "unique outlook on life." Koushun Takami, author of the original Battle Royale novel, liked how Taguchi expanded Yoshimi's backstory. Takami described the manga version of the meeting between Yoshimi and Yoji as "standing strongly on its own."(Source: Wikipedia)