Chiyo is the "crown" (the rider on top) for the girls' team. Kiyoshi is the horse for the boys' team. During the brutal fight, Kiyoshi does something that horrifies Chiyo: he to win the match. This is a devastating moment for her innocent worldview. She cannot reconcile the kind boy she loved with the one who would assault her so crudely.
In the final pages of the manga, Chiyo, with dead, hollow eyes, looks at Kiyoshi and says the last line of the series: chiyo kurihara prison school
She walks away, her innocence shattered forever. The pure angel of Prison School is broken by the very perversion she tried to ignore. Chiyo Kurihara’s story is a dark satire of the "innocent pure girl" trope in anime. She starts as the only sane, kind person in a world of sadists and perverts. Her journey is not one of growth, but of destruction . She is punished by the narrative for her naivety. The world of Prison School cannot accommodate true innocence—it either corrupts it or destroys it. Chiyo’s ending is the final punchline: the one person who believed in pure love ends up completely unable to understand love at all. Chiyo is the "crown" (the rider on top) for the girls' team