ABO Cadets - Volume 2 Chapter 48

The mysterious boy Ling Chen is saved by a little girl as he lay on the street dying. Years later, he strikes a deal to save this savior-turned sister and enters the virtual world. In a future Earth where advanced warfare has forced nations to settle issues virtually or else suffer the consequences, Ling Chen bursts into the scene and goes from unknown to legend. Yet all is not as it seems, for Ling Chen has a dark past, and there is a greater mystery at hand behind this virtual world.

To save his terminally ill little sister, Ling Chen enters the newly released virtual game world and joins a small gaming studio comprising entirely of women. From now on walking upon his path towards the pinnacle. An ancient, evil item almost forgotten by history, the “Lunar Scourge” helps forge his unsurpassable legend, and causes him to unknowingly step upon a path that is destined to be punished by the heavens, the way of the Shura.

- Description from Novelupdates

I met the male lead in prison.

“Today’s sign-in +1 is not used, please start today’s sign-in!”

“Sign in successfully, get 10 billion cash, which has been transferred to the bank account, please check.”

Ding, 10000000.00 yuan has been credited to your bank card.

“The treasure chest has not been opened today, do you want to open the treasure chest?”

“Successfully open the treasure chest, get a luxury cruise ship worth tens of billions, a private helicopter worth tens of billions!”

Chu Ping: “This system is too awesome!”

- Description from novelbuddy

A series of short stories in the world of Toaru Majutsu no Index organized into chapters featuring Kanzaki Kaori as the protagonist, going around the world and space doing missions for the Church of Necessary Evil, however, there is more than meets the eye as each incident is connected.

One chapter was bundled with each limited edition release of the Toaru Kagaku no Railgun anime DVD and BDs, with all of them together being equivalent to a single normal Toaru Majutsu no Index volume