It was the moment a century-old ironclad rule crumbled away.

"Starting this year, our school will become co-educational." The principal's declaration froze the entire student body. This was Soukyu Prefectural High School, one of the top college-prep schools in the prefecture, and a stifling garden of boys. To them, girls were "unknown creatures" that either existed on the other side of a screen or were only to be admired from afar on days off.

"Female students, enter." With the announcement, the gymnasium doors opened. Standing there were female students dressed in brand-new uniforms. Their gazes all turned to the girls at once. In that moment, their fates quietly, yet decisively, began to turn.