Infinite Dendrogram 2. The Beasts of Undeath

After an unexpectedly challenging journey, Ray and his party finally arrive at Gideon, The City of Duels.
The mere sight of the towering arenas and thriving fantasy townscapes is enough to instantly awe and enchant him. However — like anything that stands tall and proud — the city cast a great, dark shadow.
The name of this shadow is the Gouz-Maise gang — a loathsome band of cutthroats who turn their profit kidnapping children and demanding ransom.
Ray, wide-eyed and innocent, was blissfully unaware of just how cruel the hyper-realistic world of Infinite Dendrogram would become.

Source: J-Novel Club