Toaru Majutsu no Index: Genesis Testament - Volume 5, Prologue: Visitor from Picture Book Land – Girl_Name_is_“ALICE”.

The youngest princess of the country of Stellaus, Marietta, was betrothed in a political marriage to the General of the great militant country, Oltaire. General Belvant was often said to be strong, a fierce and terrifying god of a warrior. On the other hand, Marietta was a delicate flower of a princess. Everyone felt pity for poor Marietta’s situation, however, the truth was that Marietta found the General very dreamy… The story of a 30-year old General with a scary face (who was actually quite nice), and the tiny and adorable 18-year old Princess in their times of conflict and of lovey-doveyness.

One day, a mysterious tower suddenly appeared in the city. The people decided to call it a dungeon, and while it was full of rugged terrain and dangerous monsters, it was also a land of opportunity, where countless treasures awaited. When Sejun, a young man living an ordinary life, is invited to the dungeon by chance, he is thrilled at the prospect of becoming rich, but he is stranded in a hidden area of the mysterious tower. All he has is a few seeds and his body. Now Sejun must farm, collect resources, and figure out his own survival strategy!

800 years ago, 3000 dimensional gates opened across the entire world. In that moment, it was as if 3000 different colored eyes opened across the world as hordes of monsters swarmed out of these gates like tears.

Some could destroy city walls with one strike; They had bodies the size of a giant and fed on humans

Some latched onto humans, absorbing their bodies’ nutrients and enslaving humans

Some infiltrated the humans’ cities, disguising themselves as normal human beings while feeding upon human blood to sustain themselves.

In a night, the Human race fell to the bottom of the food chain.

The world had turned into a paradise for monsters…

- Description from Novelupdates