Ami Kawashima is a tall, attractive high school student who transfers to Ohashi High School midway through her second year. Before transferring, she worked as a professional model, a career she puts on hold to escape the pressures and unwanted attention of her public image. She is the childhood friend of Yusaku Kitamura, which gives her an initial connection to the school. Physically, she has long, straight blue hair and wide violet eyes, maintaining a slender and fit figure. To avoid recognition, she sometimes wears disguises such as sunglasses and modest clothing.

Her personality is defined by a sharp duality. To the public, she initially projects a sweet, kind, and somewhat clumsy airhead persona, but her true nature is arrogant, self-centered, and manipulative. Several key characters, including Ryuuji Takasu and Yusaku Kitamura, quickly see through this facade. Over time, she experiences significant personal development. A pivotal moment occurs when she confronts a stalker who had been harassing her, an act inspired by Taiga Aisaka’s fearlessness. This leads her to abandon her fake persona and remain at Ohashi High School, where she begins forming more genuine connections with her peers.

Her relationship with Taiga Aisaka starts as an open rivalry filled with mutual antagonism, including taunts about Taiga’s height. Taiga gives her the nickname baka-chi, meaning dumb chihuahua, which eventually evolves into a grudging respect and a form of camaraderie. With Ryuuji Takasu, she develops a unique friendship because he sees through her act without harsh judgment; she later develops romantic feelings for him but steps aside, recognizing his heart lies elsewhere. Her dynamic with Minori Kushieda is more tense, marked by a physical confrontation during a ski trip, but they eventually reconcile. Her friendship with Yusaku Kitamura remains a constant source of support, as he has known her true nature since childhood and accepts her unconditionally.

Ami is exceptionally perceptive, quickly recognizing the unspoken romantic feelings and emotional entanglements among Ryuuji, Taiga, and Minori. Frustrated by their indecisiveness, she often offers sharp advice and pushes them toward honesty. She also demonstrates a competitive streak, such as in cooking battles and other school events. By the end of her story, she sheds her manipulative exterior, embraces vulnerability, and finds the courage to be accepted for who she really is, maintaining close friendships with the main cast.