^ This.
Also assuming that every Kamihime has the same chance appearing (aside from bonus chance one), 5x chance for Frey would give us 5/(5+52) = ~8.8% of getting Frey when you get a SSR Kamihime. Statistically that's 50% / 75% / 95% / 99% chance of getting at least one in about 8 / 15 / 33 / 50 SSR Kamihime gotten from gatcha. That's actually quite possible to check with rerolls.
I think I didn't make mistake anywhere, but if somebody wants to correct something please do so.