Blood-C: The Last Dark.

Tokyo, Winter. Despite the use of the Youth Ordinance Bill to enforce curfews for minors and regulate the use of the Internet, young people continue to fight for their own freedom through underground methods. One such group calls themselves Surat. They have decided to take on Fumito Nanahara, a man who has great influence on the political world, and basically controls Tokyo with an iron fist. While using the Internet as a weapon to discover more information about Fumito, they learn about "Tower", the secret organization behind Fumito which engages in human experimentation.