Personal opinion, this is the kind of taste I expect when I buy a draft sake. I'm not saying this is the best, but with the sourness of yogurt and this aroma, I would buy every box.
Of all the sake from Ehime, Yamatan Masamune has been the best so far. Well, I haven't experienced Iyokagiya yet. I quite like the balance of Matsuyama Mitsui.