Official English: INKR, Azuki, Kodansha

From Kodansha:
Like many of his peers, Ataru Kashiwagi has found himself addicted to the newest social networking service, Real Account. But one day, Ataru and almost 10,000 other people, get sucked into the Real Account Zone, where they have become players in a series of deadly games. The basic rules of these games are simple—if you lose all your followers, you die in real life, and if you die, all of your followers die with you. As these depraved games decimate the players around him, Ataru must use quick thinking and his knowledge of Real Account to win each round and return to the real world. But when true friendship determines whether he lives or dies, can Ataru really survive when the only people he can count on are his Internet friends?