Is It True That I Can Be Stronger If I Make Love The Devils Daughters? is a Manga/Manhwa/Manhua in english language, Action - series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.nl fastest updating comic site. The Summary is

Orphaned after the his parents were murdered, Uta Rain was ultimately auctioned off as a slave. Certain that he would be treated terribly no matter where he was taken, Uta was in despair. But what awaited him was... a luxurious meal and five pretty sisters. However, they were the daughters of the demon lord who was defeated by the hero 16 years ago?! Uta's fate begins to change drastically!