Yeh, in the first anime, their teacher Sawako said that Ui's breasts are larger than Yui's. But, who knows what the timeline in this pic is? It could be that Yui suddenly became larger than Ui in the next season (yeh it happens!). And, maybe Nodoka was wearing a tight bra thingie that martial artist women use. At least, i think Nodoka should be smaller than Mugi 'cuz that's how i imagined it. xP