Kagerou Daze, Vol. 3 (manga)

Too much game for her own good. Takane Enomoto attends high school with only one other student in her class and a teacher who takes "underachievement" to exciting new lows. Somehow, they're going to have to put on a show for the school festival, but how does this connect to Takane's secret life as a legendary gamer? And will her legend survive the festival intact?