I've translated this the best I could. I keep getting confused about this whole "frontier" thing, as I don't watch the anime and don't know what is referring to. Anyway the joke should be clear now.
Na she's from the frontier, and they say...once...in the anime that the frontier women and men are strong people. So they likey use it as some sort of battle shout of sort.
It would have been better translated as "country", as in country women are scary. Mentioned in the game a couple times how country women are strong, stubborn, etc
GlubWell, I drink more than the average personI'm sure that must be it!Is that it?Heavy drinker of the frontierAbout 54 litersFrontieeeeeer!!!!Over 30 masuGlubGlubLiquor cellarI'm scared! Frontier people are scary!How do you get that kind of figure?Oh, I don't do anything special, really.More importantly, what do you drink?Ummm... Between unrefined sake, the special ginjo sake, Neu's milk... (Note: ginjo sake is sake brewed by low temperature fermentation from raw material consisting of less than 60% polished white rice)That night...OK, time for my evening drink...