Massive Drive

A popular mobile game called "Desperado of Treachery," where you can team up with your friends and fight other teams. Despite its popularity, the publisher decides one day that the game's life will come to an end. Himeko, a high school girl and an avid player of the game, upon hearing the news feels sad having to part with her game friends. Luckily for her, the game developer quickly changes and game service gets resumed. To commemorate this every player receives a free item lottery ticket. This way Himeko gets a rare item that makes her even more invested in the game. Then, she realizes that she feels unnaturally good during the game's battle sequences. What she doesn't realize is that the game hides a great mystery.

(Source: Shogakukan Creative, translated)