The friend in question is Maho, who Hisa has brought to the training camp in the hope that she'll prompt all of Kiyosumi's players to improve themselves in some shape or form. Her reasoning is simple enough - although Maho is a far from proficient player over all, who makes all sorts of basic mistakes and errors, she's still capable of learning quickly from the players around her with occasional but terrifying results, as Saki herself sees first-hand as a Rinshan Kaihou is used against her effortlessly.
There's little time for reflection though, as we quickly (and finally!) move on to the national tournament itself, giving us a glimpse of some potential future opponents and their powerful mahjong abilities, while also informing us very quickly that Kiyosumi have breezed through their first match, leaving them to rev up for their second and far more challenging match. In other words, the series is really going to start now, and not a moment too soon.
I'm trying to be patient, I really am, but three episodes of build-up and training camp have done nothing for my enthusiasm towards Saki - the show simply doesn't have a whole lot to offer when it isn't involved in tense, must-win mahjong hands, and even training sessions can't recreate the rollercoaster of tension generated by those games. Thankfully, the series has decidedly to fast-forward to the core of the national tournament at last, so all of these complaints should dissolve next week, right?