From Yen Press:
No matter how much the times change, bullied kids aren’t going anywhere. And fat junior high school student Haruyuki is one of them. But one day, Haruyuki encounters Kuroyukihime, the most beautiful and elegant girl at school, who gives him a mysterious program: “Brain Burst”…and the secret of the “Accelerated World.” He may be at the bottom of the food chain at school, but Haruyuki and his destiny begin to “accelerate” with incredible speed in the virtual realm as he aims for the top.

Chigira Chiaki loved the tales of Kuroyukihime and Black Lotus her beloved elder brother told her about.

Returning to Japan after a long stay in America, Chiaki entered the Private Seibi Academy for Girls. There, she met the club members of the Enbuken and starts her journey into the Accelerated World.