"So how exactly does your magic work?" Aaron asks, as Erica leaves the room "Do you need to have sex to take energy?"
"No," Anna said "Intercourse brings the energy to the surface which makes it easier to draw it. Anything that causes exertion would work, so combat would also be a time I could train, or while you were working out."
"And you said that makes it easier? So you could take energy without the exertion?" Aaron said
"That's right," said Anna "Up to my limit, anyway. If I go over my limit, I'll grow another tail, which will greatly increase my power in the short term, but I'll crash out after that. The tail will remain, and permanently increase my limit, but I've never gone above it yet."
"So you were born with two tails?" Aaron asked
"No," said Anna "I met another kitsune when I was 18. He wanted to become female permanently, and I wanted to help. We found that kitsune can transfer their energy to other kitsune at an accelerated rate. This kitsune took my virginity, and allowed me to absorb so much energy, I grew my second tail."