Kaori Munakata is Shuichi Natsume's girlfriend. She first appears alongside Shuichi when they meet his younger brother, Akira Natsume. Kaori immediately introduces herself to Akira, mentioning she's aware of his talent for repairing electronics despite his phobia. Prompted by this knowledge, she asks him to look at her malfunctioning smartphone, which has no sound output due to problems with the earphone connection. Akira quickly diagnoses and fixes the issue. During the repair, Akira experiences dizziness, loses his balance, and accidentally falls onto her chest, leading to his immediate apology. Kaori reacts without anger, dismisses the incident lightly, and humorously suggests he might become her brother-in-law someday. To commemorate their meeting, she takes a selfie with Akira.

Her surname, Munakata, references the Three Munakata Goddesses from Japanese mythology. These goddesses, born from the debris of the Sword of Totsuka wielded by Susano-o, are associated with the sea and revered as deities of maritime safety.