The fact that he speaks the Osaka dialect is an important part of the story and has an alienating effect. Kitaru is rather short, small-boned, and has noble features, so when he opens his mouth the contrast is really striking. I wasn't sure how to handle this in translation.
The usual wisdom in translation studies is to not even try translating a dialect, because one ends up localizing it in the wrong place and the effect can be comical.
Edward Seidensticker referred to this issue in remarks he made years ago about his translation of Sasameyuki (The Makioka Sisters):
Having read the above, I felt a little disheartened not knowing what to do about translating Kitaru.
Let's look at the first conversation between the two male students appearing in the story:
It is clear from the very first words that Kitaru "sounds different." This is how this conversation was rendered by Philip Gabriel:
From this short fragment, it seems that Gabriel did what Edward Seidensticker wished he had done: put more contractions in the Osaka speech. I did not have that option in Polish, since Polish doesn't really use contractions. I briefly considered making up a dialect, but did not feel equal to it. After a lot of hesitation and looking at some other translations, I decided to try an experiment, which I will describe in the following post.