The Black Dog of St. John's

Is it a human hand, or a beast’s paw? Adriel Merryweather, the only son of a family with no reputation to speak of, is admitted as a transfer student to “St. John’s,” one of the most prestigious boarding schools, after tremendous effort. Although he entered St. John’s to fulfill his parents’ hopes of restoring their declining family fortune, he had an even more important goal. That was to uncover the truth that Jeremiah Washburn, a current student at the school, is actually a demon in the form of a black dog. “Long time no see. Nice to meet you.” However, on his very first day at school, Adriel unexpectedly runs into Jeremiah again, and ends up making the worst mistake imaginable right in front of everyone... (Source: Ridibooks, translated)