Roommate to Nazotoki wo

Togawa Hinata, a small boy attending Kirimori Academy, an all-boys boarding school, lives in the old dormitory, Asunaro Hall, which has only six residents. Takamiya Echika, a tall transfer student who arrived at the start of the new semester, moves in as Usagawa's roommate. Usagawa is excited about this new encounter, but Takamiya speaks to him bluntly, and the two are at odds with each other from the very first day. Even as they argue, Usagawa realizes that Takamiya has the insight of a detective in a TV drama... A youthful school mystery unfolds as the mismatched roommates take on the mystery of a murder case. (Source: Natalie, translated)