I was trying to figure out what the hell she was doing with her legs when she slashed him, but then I realized it was just to hide her underwear from the panel.
I can't tell if it's meant to be said awkwardly or that's just a natural way of referring to the practice in Japanese. A more natural way of saying it in English would be "I'm fasting for Ramadan" which is equivalent to "I'm fasting for July."
That brings up something that was bugging me. How did a nobody middle duchy like Ehrenfest manage to maintain neutrality through the bloody civil war when this much smaller scale succession dispute is forcing them to take a side?