All eleven episodes of the Japanese anime set in an alternate Tokyo that has been devastated by a terrorist attack. Six months after the disaster, a cryptic video is posted online by two masked teenagers named Nine and Twelve (voices of Kaito Ishikawa and Soma Saito) from the organisation Sphinx. Together, the pair baffle police with their riddles and vow to tear the city apart with more deadly attacks.

The episodes are: 'Falling', 'Call & Response', 'Search & Destroy', 'Break Through', 'Hide & Seek', 'Ready Or Not', 'Deuce', 'My Fair Lady', 'Highs and Lows', 'Helter Skelter' and 'VON'.