To the lighthouse
I am mostly a fan of Meredith WEATHERBY's translation of Mishima's Shiosai (潮騒, "The Sound of Waves"), but I think his decision to totally ignore the dialect the characters speak was the wrong one. Mishima sets his exquisite Standard against kanji-assisted islandish to striking effect:
「もう恥ずかしくないやろ」
と彼が詰問するようにはげしく問いつめたので、少女はその言葉の怖ろしさも意識せずに、思いもかけない逃げ口上を見出したのである。
「ううん」
「なぜや」
「まんだ汝(んの)は裸になっとらんもの」
But Weatherby renders everything in a fairly neutral English:
"Now you're not ashamed any more, are you?" He asked the question at her as though cross-examining a witness.
Without realizing the enormity of what she was saying, the girl gave an amazing explanation:
"Yes..."
"Why?"
"You—you still haven't taken everything off."
Dealing with dialect is tough, though, and I have no idea what drove this decision for Weatherby, so he gets a pass. But it did make it all the more surprising when he left some dialect in—and in Japanese, no less:
"Immorality?" asked Hiroshi. "What do you mean?"
"Don't you know, Hiroshi? I mean what your brother Shinji did to Miyata's daughter Hatsue—I mean omeko—that's what. And that's what the god is angry about."
"Omeko"—in the original Mishima gives this the ateji "交接", which would normally be pronounced kōsetsu and mean "sexual intercourse". So it's pretty clear to the reader what this means, even if they haven't heard that particular slang before.
Having a dirty mind, I looked it up; turns out it is used all over western Japan (and as thieves' cant in the east by the Taisho period at latest), and that it originally referred to the female genitals rather than any particular use to which they would be put. MAKIMURA Shiyō's Osakan dictionary has this to say:
Derogatory term for the female genitalia. Perhaps from 女子 (meko, woman-child)? In women's language, ososo. [Osakans] never said omanko, bobo, etc. In the Sangetsu Hall of Tōdaiji in Nara, there is a wooden statue of Daikoku known as the "Omeko daikoku". This is because his right hand is forming a kongō-ken, which looks like an me-nigiri ["woman squeeze"], in which the tip of the thumb protrudes from between the index and middle fingers of the fist [representing, again, the vagina].
The more you know!