There is a certain degree of it with Nodoka, but the real grower seems to be Awai (the blonde girl in the current match). She first showed up in chapter 56, and was basically flat. Every single cut scene that showed her (generally talking with Teru) seemed to have her breasts grow larger. And now that they're in the match, her breasts are gargantuan. (See her resting them on the table during match setup in the last few chapters.)
My suspicion is that her breast size is tied to her powers in some way. Just like some other characters increase in power over time (for example, Shizuno in the current match gets stronger the further into the wall they go), my thought is that they represent her accumulated power for the tournament. That's probably also why she was put in the captain position, in order to maximize that benefit.
Most other characters do not seem to change over time. Those with large breasts may gain a little bit (Nodoka being the most egregious example), but the flat girls stay flat. The fact that Awai started flat and grew to gargantuan proportions is definitely the anomaly.
