女は内に means 女は（家の）内に（いるべきだ）, i.e., Japanese traditional way of thinking.
Ok, that was my guess by the rest of passage.
I have to think about how to translate some of those passages and still make sense, there are some cultural differences I have to consider.
Since Ohira seems to be always hitting on Asako I suppose that 「――変りもん同士で、面白くやってゆけると思うんだがな……自由に……」 could be translated as "We are both weirdos, maybe we could have some fun (together)... No strings attached...", right?
And after Asako leaves the room, Sachiko says 「おや、いなかったの！」 could I translate it simply as "Hey, where are you?" instead of literally "Hey, aren't you there?"