Kura Nama Hito: Cloud(2011)

Kura Nama Hito: Cloud

The Tokyo Metro central computer has been cracked! Out of the chaos of wild passengers and a frantic transport ministry, Cloud's story begins. A child prodigy who has grown up into a black hat hacker strives to fulfil his impossible dream of making a kingdom on top of the clouds! But how will he do this and what will the government and police even allow him to try?

(Source: Shinchosa, translated)