Welcome to the cruel game of survival. If you hold a Future Diary, you're a possible target for the game to get the rank of God. And everyone else has some type of Future Diary too.
This is the plot where Mirai Nikki revolves in. But the manga explains how the game is started. How? Yukiteru, the main character, is pretty much an outcast. Left without friends, Yukiteru begins to create imaginary friends like Deus Ex Machina, the 'Lord of Time and Space.' However, creating this 'Lord' comes with a price; creating 11 Future Diary holders.
This is definitely something unique. Never really seen something like it before. The pacing can get a little too fast though.
And now, the characters. Yuno is your typical overprotective person, protecting Yukiteru and becoming obsessed with him. But there's a twist... she's a yandere, someone who'll even kill someone else to 'protect' his/her lover. Definitely something good coming your way. But then, comes your typical backboneless character, Yukiteru himself. But he develops well. And the other ten Diary Holders, too. You'll be turning the pages crazily, learning about each and every Diary Holder and their personalities.
Can't say anything much about the art, though. Pretty average and serves its purpose well.
Overall, I've enjoyed this manga very much. Brutal scenes line the pages of this manga, and don't expect a touching and cute romance. You're in for a ride.