Kyoko Takimoto is a high school student and the best friend of Sakura Yamauchi. She possesses a slim build and short brown hair that ends at the bottom of her neck, featuring uneven bangs swept upward over part of her forehead and thick, short locks framing her face. Her thin eyes hold reddish-brown pupils, and a small mole rests beneath her left eye. Following Sakura's death, her hair grows longer, reaching just below her chin. Kyoko typically maintains a serious or aggressive expression.

She exhibits a cold, aggressive, and stubborn demeanor toward those she deems suspicious or untrustworthy, particularly Haruki Shiga. She repeatedly attempts to convince Sakura to avoid Haruki, though her efforts are consistently rejected. Despite this outward harshness, Kyoko shows sweetness and fierce loyalty toward close friends like Sakura, a facet of her personality that becomes more apparent after Sakura's death.

Kyoko first appears by interrupting a meal between Sakura and Haruki, mistakenly assuming it is a date and criticizing Sakura's choice of company. She is later seen disciplining a classmate, Issei Miyata, for neglecting his chores and directing a hostile glare toward Haruki. A confrontation unfolds on a school balcony where Kyoko questions Haruki about a trip with Sakura; after receiving no answer, she knocks Haruki's book off the balcony and threatens him should any harm come to Sakura. During a hospital visit, Kyoko witnesses Sakura and Haruki embracing, which sparks an anger that Sakura diffuses with an enthusiastic greeting. Kyoko attends Sakura's funeral, mourning alongside other friends.

After the funeral, Haruki invites Kyoko to a café and provides her with Sakura's journal, "Living with Dying," to read. Upon learning of Sakura's terminal pancreatic illness, Kyoko breaks down. Haruki subsequently asks her to be his friend. One year later, Kyoko and Haruki visit Sakura's grave together, indicating a developed friendship. During this visit, Kyoko offers gum to Haruki, a gesture hinting at a potential relationship with Issei Miyata, who is frequently associated with gum. They then proceed to visit Sakura's family.

Kyoko and Sakura share a deeply close friendship defined by mutual care and concern. Kyoko's protective nature toward Sakura fuels her initial aggression directed at Haruki. Their relationship begins negatively due to her actions but evolves into a friendship by the story's conclusion. Her interactions with Issei Miyata involve a love-hate dynamic, with Kyoko often physically chastising him for his laziness. The live-action adaptation confirms Kyoko and Issei's marriage, and the sequel novel, *To My Father and to Someone in My Memories*, reveals they have a daughter named Anzu.

Kyoko's name incorporates the kanji for "waterfall" (滝, taki), "origin" (本, moto), "respect" (恭, kyō), and "child" (子, ko).