I am the first person to ever write a review about this series and so I'll be as brief as possible. It's ok, not great as it could have been, not bad as it could have become, but just ok...an easy 6 out of 10 with an incomplete story, a pretty art style, some one dimensional characters and a feeling of emptiness. The 23 chapters have some highs and some lows, but for me the lowest points of the manga have to be Sagawa's backstory and the ending...both of them making reading the manga a monumental task, Other problems I had were with the world building,if humans always had butterflies then why isn't this reflected in their culture? We know next to nothing about humanity before the apocalypse that killed 2/3 of the population and it feels like we should, there is so much the author could have done and instead we have this....an incomplete piece of story that just ends with the promise of a continuation that will never happen.