Yoriko Kosaka

Yoriko is cheerful, friendly and affectionate, particularly toward Touka Kirishima. She enjoys spending time with her and frequently expresses that friendship by cooking meals and snacks for her.

Cooking is more than a casual hobby for Yoriko. She takes pride in preparing food for other people and wants to pursue it professionally. Her enthusiasm repeatedly creates an uncomfortable situation for Touka, who cannot safely digest ordinary human food but accepts Yoriko's cooking to avoid hurting her feelings.

Yoriko's friendship with Touka is uncomplicated by the prejudices that define much of the wider story because she does not initially know that her friend is a ghoul. She values Touka based entirely on their years together as classmates and friends.

Yoriko is an ordinary human with no kagune, quinque or combat training. Her role remains rooted in civilian life rather than the conflict between ghouls and the CCG.

Her most developed skill is cooking. She regularly prepares food for Touka Kirishima while attending Kiyomi High School and hopes to turn that interest into a profession.

By Tokyo Ghoul:re, Yoriko has pursued that ambition and works at the bakery Oasis. Her career keeps her largely outside the violent world surrounding Touka even as circumstances eventually pull her into the conflict.

Yoriko attends Kiyomi High School with Touka Kirishima and is her closest human friend. She regularly shares food with Touka without realizing that eating ordinary human meals makes ghouls physically ill.

Her presence provides Touka with a reason to participate in ordinary school life. Yoriko talks about their futures, shares everyday concerns with her and wants their friendship to continue after graduation despite having no knowledge of the dangerous life Touka leads outside school.

During Tokyo Ghoul:re, Yoriko works at the bakery Oasis and becomes acquainted with CCG investigator Takeomi Kuroiwa. The two develop a relationship and eventually marry.

Tooru Mutsuki later exploits Yoriko's friendship with Touka by having her arrested under accusations of concealing a ghoul. Evidence of Touka eating Yoriko's food is used against her, and she is sentenced to execution under the CCG's laws. The case is part of Mutsuki's attempt to force Touka into exposing herself.

Yoriko survives the ensuing collapse of the old CCG system and reunites with Takeomi. Years after the conflict, the two have a son.

Touka Kirishima is Yoriko's best friend from Kiyomi High School. Yoriko regularly cooks for her and wants their friendship to continue beyond school, never realizing at first why Touka struggles with human food. Even after years apart, their friendship remains important to both women, and Touka secretly watches Yoriko's wedding while avoiding direct contact that could endanger her.

Takeomi Kuroiwa becomes acquainted with Yoriko while she is working at Oasis. Their relationship becomes romantic and the two marry, making Yoriko part of the Kuroiwa family. They later have a son together.

Iwao Kuroiwa is Takeomi Kuroiwa's father and therefore becomes Yoriko's father-in-law through her marriage.

Tooru Mutsuki targets Yoriko because of her connection to Touka Kirishima. Mutsuki engineers her arrest and threatened execution in an attempt to lure Touka into CCG custody.