During the initial Outbreak at Fujimi, Kawamoto was part of a group of five including herself, Takuzo, Naomi, and two other male students. Though she came onto the minibus with Takashi's group, she sided with Shido and became one of his followers. Her mind becomes twisted and she engages in sexual intercourse with another female follower: Taniuchi. It is implied that she is lesbian or bisexual.
Kawamoto is a red-headed girl with golden brown eyes. She has only been seen wearing the female uniform of Fujimi Academy. During her "free time" with Taniuchi and Miura, she is shown to have a pink (white in the anime) tanktop, but no bra, under her uniform.
Not much is known about Kawamoto's personality. Given the fact that she does not wear a bra and was seen making love with Taniuchi and Miura, it is possible that she is bisexual. She seems to be the more outgoing and tomboyish of the pair, and also appears to have a girl-crush on Shido given her small blush when Shido hugged her and Taniuchi to calm them when they witnessed some police men killing one of Them. Like her friend, Kawamoto has become quite cruel and mean-spirited due to Shido's corruption, best demonstrated when she laughed at Yamada who was kicked out due to disagreeing with Shido's ideals.
During the attack on Fujimi Academy, Kawamoto is first seen with Takuzo, Naomi and two other students fighting Them on a stairwell. They are about to be overtaken when Takashi's group arrives and eliminates Them with relative ease. Naomi confirms that none in their group have been bitten and accepts Takashi Komuro's offer to join in their escape to the school.
Kawamoto and her now unified group arrived at the front entrance only to find that it was plagued by Them. Takashi went down to test Saya Takagi's theory if They only respond to sound. He threw a shoe at a locker, which caused the undead to walk towards the other side of the room. With the cost clear, Takashi gestured for Kawamoto and the others to move and they headed out the door. Things went smoothly until one of the boys from Takuzo's group accidentally banged his pole on the railing. The noise echoed throughout the school, attracting the attention of Them. Takashi yelled for the group to run and they ended up having to fight their way to the minibus. Along the way, Takuzo was caught and bitten and Naomi rushed back to die with him. Kawamoto and the other two boys were able to get on the bus with Takashi's group, however. Just as they were about to leave, they spotted another group of survivors lead by Koichi Shido, the teacher of class 3-A. Despite Rei's protests, Takashi allowed them to board, apparently not witnessing Shido's stomping of one of his students when he fell and sprained his ankle. Shizuka Marikawa drove the bus through the front gates and left the overrun school behind.
After driving for a while, Kawamoto was seen comforting a crying Taniuchi while Tsunoda, another student who came with Shido, complained about being brought into the city without his consent. Shizuka nearly got into an accident with another driver because of his yelling, which caused her to tell him to be quiet. This only got him more angry, causing him to vent his anger out on Takashi. The conflict almost resulted in violence before Rei Miyamoto instantly intervened and struck him down. Shido took advantage of this incident to prove to the others that a leader would be necessary in order to survive. He told the students that if they joined him, he would do anything to prevent future conflicts. Finding inspiration in his words, Kawamoto got up immediately after Taniuchi and applauded in approval. This angered Rei, who got off the bus, saying that she did not want to stay with Shido any longer. Though Takashi tried to get her back on, another, larger bus that was under attack by Them speeded out of control towards them, cutting them off from the group on the bus. The gang on the bus was forced to find a different route to the city.
During an anime only scene on the minibus, Kawamoto and Taniuchi became frightened when they witnessed some police officers killing one of Them. Shido embraced the both of them, ensuring that they were all safe in the bus. The comforted girls blushed at his "kindness", failing to notice the maniacal look on their teacher's face.
The next day, Kawamoto and the others continued to listen to their leader's speeches and promises, the girls in particular staring at him in awe, almost obsessively. They were surprised to hear that Saya and the other members of Takashi's original group were leaving them behind to pursue their own goals. Shido tried to get at least Shizuka to stay, but he was foiled when Kohta Hirano shot a nail at him. The four left the group behind, much to Shido's frustration. Upon Kawamoto asking him if he was alright, Shido put up a cheerful front, saying all who were standing in their way had left.
Later, after Shido's group is able to somehow cross the Onbetsu Bridge, Shido allows his followers to do whatever they wish, calling it "free time". Kawamoto has lesbian sex with Taniuchi and also with Miura. Shido gives another speech on how his students are angels who will lead the new world and about how he is hoping that the students can purify him of his sins. This brings Kawamoto to tears and she applauds Shido along with everyone else. When another student named Yamada, voices disapproval and says that he wants to find his family, Tsunoda and Yuuki taunt and have sex in front of him, saying that they would follow Shido anywhere. Shido talks his students into rejecting Yamada off of the bus for the sake of the new world. Yuuki gets everyone to vote for Yamada's expulsion and back him into a corner. Miura and Tsunoda throw him off of the bus, making Kawamoto and the others laugh at him as he fails to reboard and he is subsequently killed by one of Them.
Upon arriving at the Takagi Estate, Kawamoto is seen holding Taniuchi's hand as well as having her other arm wrapped around her, smiling contently. They witness Rei's confrontation with Shido and watch on as she prepares to kill him, only to retract moments later, deciding that he was not worth the effort. Kawamoto and the others are forced to leave the Estate, as Souichiro has declared them too corrupt.
- The surname Kawamoto means "river, stream" (川) (kawa) and "base, root, origin" (本) (moto).
- Kawamoto's last name is not mentioned in the anime or manga. It was only revealed in her profile in Highschool of the Dead: TV Animation Complete File.
- During the bus orgy scene in the manga, Kawamoto's tanktop was pink.
- In the anime, it was white.