Although i have only seen one episode i can be certain this series will be a great one. Its kind of like Eden of the east, people with cellphones that end up in a survival game with the winner being the last person holding this future telling cell phone the winner or new god.
These cellphones tell each of the 12 peoples who are chosen their own future. It is a diary written specifically for them.
The story for me is a cross of Eden of the East and Steins Gate (but futuristic not past)
Over all great story even if it is similar to some animes, it is also completely different so far.
I can presume they will explain each of the twelve characters over the series.
Overall, great voice actors, love the music, the art is beautiful for the characters, kind of reminds me of Noein art wise especially for the "God".
I really hope this story continues to be epic, as this series is must watch!