My name is Haoxuan, and I am a Chinese college student studying in Japan. I am born with a very strong thinking ability, and I am particularly interested in reasoning. I love to study various murder methods, find a breakthrough, and finally solve the case. I particularly enjoy this feeling. There is nothing happier than this in the world. When I was a college student, I found four roommates from all over the world who were interested in reasoning: Er Ge, Guo Xiaoming, Lan Xiao, and Shi Yue. An informal detective team was formed to participate in criminal reasoning. Wherever we arrive, we are always faced with the occurrence of murders and the truth of the matter. Let us uncover them one by one. My name is Haoxuan and I am a detective.