No. 6

This has to be one of the most amazing Animes out there.

Only 11 episodes long, No. 6 takes you to a futuristic world where there are only 6 major cities in existence. No. 6 is meant to be a heaven, a happy place to live although there is something not quite right. People disappear without a trace and there is a strange illness that ages and kills with no explanation.

Shion, a young yet brilliant boy of 12 runs into one of these missing people. He helps the young boy, called Rat, and gets blamed for it. Later loosing his scholarship and ending up working for the government at age 16. More here. (I don't want to spoil it too much ;) ).

This story is amazing. The ending is just perfect. You MUST watch this one, you won't regret it!