From KobatoChanDaiSukiScan:

In a world where four chosen races exist, the world is divided into two. One half is the jungle where the Nagas reside, and the rest is inhabited by the humans, Dokkaebis, and Leckorns. A party of three, consisting of a human, a Dokkaebi, and a Leckorn, infiltrates the territory of the Nagas to rescue a Naga.

Note. A third-person action role-playing game of the same name, based on this novel, should be released around 2027. This game is being developed by the Canadian company KRAFTON Montreal Studio, a subsidiary of the South Korean company KRAFTON.