Bullet Code: Firewall 2

is the second volume of the Bullet Code light novel series, written by Suzu Saito and Illustrated by Wata. It was released under the Dengeki Bunko Imprint in August 2021.

Synopsis
Yuma Furuhashi and his friends who survived the harsh battle of cyberspace and returned to reality while losing many friends. However, one of the key players, Chitose Amemiya, a girl who had the nickname of "Frostbiter" and swore her future, had a certain change. Her partial memory loss. She had lost her memories of Yuma, who grew up in the battle. Yuma tries to face her as her lover again, but a person appears there. Chitose's older sister, Shiro Amemiya, the strongest woman in cyberspace. In order to confront the threat that will come again in her near future, Yuma looks up to Cretaceous as her teacher and tries to train herself.

(source: Dengeki Bunko Official Website - Translated)