Gaku is the son of former Japanese national volleyball star Kei Shishiya. Through middle school, he's played as his team's ace hitter, though part of him wonders if that's a title he earned, or one he was simply given. One day, Kei meets Noboru, a generational volleyball talent with a monstrous spiking arm, and vows to turn him into the next national standout. In the wake of that choice, Gaku realizes he can't play the style his father demands, but swears he'll defeat both Kei and Noboru with a game that's entirely his own.