For future references: the note over the title had it translated as "Miss and Yukkuri"
According to pretty much every other translations, "Miss" is "Onee-san", while here it's "Ojou-chan"
Since "Ojou-sama" is usually translated as "Mistress", as it's said by Sakuya referring to Reimilia (not just in the yukkuri universe), I changed the title to "Lady and Yukkuri"
If someone has something better I'd like to know it