Ren Mihashi is a pitcher who refuses to leave the mound, for better or worse. His middle school team hated him for it, blaming him for their continuous losses and chalking up his starter position to favoritism. In the end, Mihashi ran away to a different high school, convinced that he would never amount to anything in baseball.

Upon his enrollment at Nishiura High School, however, he is quickly pulled into the newly formed baseball team with people who recognize his abilities. Mihashi is paired up with the gruff catcher Takaya Abe, who promises to bring out his full potential as an ace—so long as he never disobeys his directions. This marks the start of Mihashi's journey to build the strength and confidence needed to stand with his new teammates on any field.