Having reached the final qualifier match for the Nationals, Karasuno must now push themselves beyond their limits in order to defeat Shiratorizawa.
Continuing from where the second season left off, this one covers the single titular game between the two teams. While it’s the same mix of comedy and hot-blooded sports action as always there’s not much point in jumping into the series here, so if you haven’t yet seen the prequel(s) you should do so before attempting to watch this.
More Information:
aniDB
Crunchyroll
Fansub.co
Wikipedia