Okay, previously I recommended a new work by this author; Otogi Taisen Phantasma, so I thought I'd recommend his previous work. Which was what made me interested in his works in the first place. If I had to describe this story, it would be brother with sis-con gets involved with a secret underground fighting tournament that involves clones of his dead sister.
Yeah...so the main character is yet another snarky boke dude. His adopted sister was murdered years ago and they never found the murderer. His adopted brother disappeared for years following that and he just sort on went about on the normal route of life, going to High School, etc etc. Then one day, he decides to look into his sisters murder and then he meets a clone-doll of his sister.
I say clone-doll because that's the only way to really describe them. They're life-sized dolls; much like Rozen maiden, that have had parts of his sister implanted into them. They act a lot like human beings and probably can be considered living much like sentient robots. They're also all participants in a deadly fight to the death to be last living Ayame (the sister). The one who survives is Ayame, the rest are merely useless dolls. It's like some sort of existential survivor/battle royale.
The mastermind behind this battle royale though? The protagonists; Kansuke, adopted brother, in a twisted scheme to bring back his sister. Kansuke realises that his brother needs to be stopped and that even though they're dolls, they're still living (kinda) beings with their own mind and personality and having them fight to the death is wrong. The best moment has to be when he's asked why he's trying to protect all of them, he claims it's because they're ALL his little sisters because they have a little bit of his sister planted in them.
Sadly, the manga is over by now and it was pretty short. Only 20 chapters and it felt kind of rushed towards the end, which usually means it was cancelled. Which is a pity because I found it pretty interesting but the art style can be pretty raw at times. Thankfully, the artist seems to have gotten better with his later works.
Overall, I'd say this is worth a read and can easily be finished in an afternoon since it's only 20 chapters.