Eroi Koto Suru Tame ni Kyonyuu Bishoujo Dorei o Katta Hazu ga, Oshishou-sama to Shitaw is a Manga/Manhwa/Manhua in english language, REINCARNATION series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Halo is a talented female elf magician who has memories of when she was a man in her previous life, which is why she wishes to make out with a cute girl. Halo decides to buy Filia, a beautiful female slave with big breasts, but things don’t go as she expects them to...