Accel World

Accel World (アクセル・ワールド) is a Japanese light novel series written by Reki Kawahara and illustrated by Hima. It has been adapted into two manga series and it was also adapted into an anime in 2012.

Story
In the year 2040, Neuro-synchronization, a technology system that allows humans to manipulate their five senses has become widespread where people can access the internet and enter virtual worlds. Haruyuki "Haru" Arita is a short, fat boy who is constantly bullied, causing him to have a low-self esteem. To escape the torments of real life, he logins in the school's virtual world network where he plays squash alone where he always gets the highest score. One day, Haru attract the attention of the Student Council Vice-President, Kuroyukihime, who offers him to join a secret program called Brain Burst which allows a person to make time appear to stand still in their surroundings by "accelerating" their brainwaves in the real world. Unfortunately, there is a limit to how many times a person can accelerate which uses Brain Burst points and the only way to get more points is to fight other Brain Burst users in a Fighting game and defeat them. However, if a user loses all of his/her points, the Brain Burst program will uninstall itself and the user's memories of Brain Burst will be deleted. Kuroyukihime wants Haru's help as she wishes to reach Level 10 and meet the creator of Brain Burst and learn it's true purpose. But in order to do that, she must defeat six Level 9 users who just so happen to be "The Six Kings of Pure Color", the leaders of the six most powerful factions in the Brain Burst world. For helping him, Haru agrees to help Kuroyukihime to not only repay her but overcome his weaknesses.