Tweekums As this series opens protagonist Basara Toujou learns that his father has remarried and his two new step-sisters, Mio and Maria, will be moving in; shortly afterwards his father has to go away leaving him alone with the two girls. It turns out these aren't ordinary girls, Mio is a demon princess and Maria is a succubus! One might expect Basara to be a little shocked when he learns this but he isn't; it turns out he is a member of the 'Hero Clan'. As such the girls should be his enemy but after a short while they start to get along. For reasons I won't spoil Maria creates a magical master-slave bond between Basara and Mio; any time she fails as his slave she gets highly aroused! For the first half or so of the series we get mostly comic episodes but then the atmosphere changes when a threat emerges; then Basara and the girls must fight magical battles to survive.This is a fairly mixed series; starting off with lots of comedy, amusingly awkward moments and fan service… although the last of these is fairly heavily censored; presumably the 'steam' will be gone in the DVD release but I wouldn't be surprised if other censorship remained. The comedy is for the most part highly sexual, in ways that may offend/embarrass some viewers while amusing others. When the more dramatic episodes begin it abandons most of the comedy and becomes a magical fighting show leaving one wondering if it is the same series you are watching! The characters are fun enough; especially Mio and Maria who can be hilarious at times and the animation is as one would expect from such a series. The final scene promises a second series will be made. Overall I'd say this isn't terrible but neither is it a must-see series.These comments are based on watching the series in Japanese with English subtitles.