Accel World (2012)

Haruyuki is an overweight kid and at the bottom of the food chain at his middle school. Within the sci-fi setting of the real world he often seeks refuge in a virtual one. One day however his life changes when he is given an opportunity by the prettiest girl in the school no less, to integrate the two by means of a program called accelerated world (Brain Burst). There is a catch however, in order to keep this add-on he must score points by fighting others within the realm of this new virtual world.