Dungeon. A scary place, with different levels. There are 16 levels in total, but people only explored 10. The dungeons had their own rules and priorities. And even in the dungeons there were rulers and aristocrats.

In the dungeons there were also those who were commonly called 'brats' or 'failures'. These were people born in the dungeon. The higher the level they were born on, the stronger they were. Usually, those born below the 9th floor either died or were never found. But, Satoru and Suguru were the ones born on the 16th floor.

They both saw nothing but monsters trying to eat them. It's either you or they. The older they got, the stronger they became. Now, they were 14. Another day, they killed monsters and walked through the dungeon floors, collecting soul stones. Until they came across a group of people. Satoru looked at them questioningly

— "...who are you?" — he asked