Interracial Detective Agency

In this world, humans are not the only highly intelligent creatures that exist. There are many other races that have their own civilizations like humans. These races have established their own countries in different regions of the world. Our protagonist is just a small citizen of the human kingdom. He lives in an inconspicuous town. After experiencing some things, he no longer only accepts entrustments from human society, but also some creatures from other races who come here to entrust him with cases. In this way, our protagonist led his biological sister to solve one difficult case after another...