Ookami wa Tantei wo Tabetai

I have no confidence that I can "wait."

"Werewolf Syndrome"—The spontaneous onset of a strange disease. Those who are affected present symptoms such as attacking and devouring humans. In this world, this is merely an urban legend, but, ten years ago, Reito's brother was killed by a werewolf. Since then he has spent his life as a lone detective in order to expose the truth behind werewolves. Under such circumstances, he meets his estranged nephew for the first time in ten years. Reito was briefly surprised to see that Yoru, who used to be a crybaby, is now a dashing university student who towers over him. Shortly after, Yoru suggests that Reito should hire him in the detective agency...?!

(Source: Square Enix, translated)