Kokoro Shiina is a secondary character in the series Hajimete no Gal. She is a high school student and a close friend of Yukana Yame, belonging to Yukana's circle of gal friends. She has blonde hair that is styled into twin tails tied with red ribbons and drooping eyes. In the manga, she appears mostly as a background character, but her role is more prominent in the anime adaptation. Her relationship with Yukana is that of a supportive friendship, and she often spends time with Yukana and the other gals. No specific personal motivations or character development are highlighted in the story, and she does not possess any special abilities. Her function within the narrative is primarily as a member of the supporting cast, adding to the social circle around the protagonists.