I think the "Gothic" and "Mincho" styles are mixed quite often, even in magazines/newspaper-like publications, like sans-serif and serif fonts are mixed in Western publications. Ads have all sorts of different typography, and Mincho is always the type for all situations, like Times. So of course there are Kaku/Maru fonts mixed with Mincho. How fortunate such a union is, really depends on taste, and I think typographical sense is really quite different in Japan.
Hermann Zapf was once working together with a Japanese typographer on a Japanese font for some time. Eventually they had to abandon the project, however, because they were unable to unite the Western and Japanese ideals. In particular, Zapf was hoping to create a font with even distribution of darkness, which contrasts the need for Japanese characters being light or dark, as kanji are partly recognized by their tone.
To come back to the question, I think successful blends can be achieved, but they may be successful only for one particular taste of typography.