Saki: Nationals, or Saki: Zenkoku-hen, is the follow-up of the first Saki anime, which ended with Kiyosumi High School qualifying for the national tournament.
It’s definitely Saki. The first episode introduced a whole myriad of new characters, Saki got lost again and Yuuki is still obsessed with tacos.
Also, the reason for Saki’s longer skirt was explained, which I think was pretty neat.
Looking forward to more Saki: Nationals, especially once the nationals get started proper.