Synopsis
Hajime Iwaizumi is Aoba Johsai's vice-captain, ace, and wing spiker, and Tooru Oikawa's childhood friend. Iwaizumi was there for the Japan–Argentina match that set Oikawa on the path to becoming a setter, and has spent the years since watching that determination grow into something close to obsession.
Stubborn but dependable, Iwaizumi often steps in as the team's steadying presence whenever Oikawa's self-doubt threatens to take over. He doesn't hold back with his captain — routinely knocking sense into him whenever the teasing goes too far — but the affection underneath is genuine: he once stopped Oikawa from striking Kageyama in a fit of blind rage, talking him down by pointing out that no one beats a player like Ushijima alone, which is exactly why a team exists in the first place.
Underclassmen gravitate toward Iwaizumi for advice, and even rivals respect the fairness he brings to the court. After graduating, Iwaizumi studied sports science in college and became an athletic trainer working with Japan's national volleyball team.
