Enomoto-Senpai Wa Tenshi Nanka Janai summary:

In the room of Hagino (university student), there is a ghost (?) of a man who was supposed to have died in an accident. That is Enomoto. Enomoto is the best friend of a senior student whom Hagino has a crush on, and is a bold man with a mean look in his eyes. Like the Grim Reaper, Enomoto declares, "If I can take my best friend's life within 49 days, I can come back to life in his place." A BL story of secret nemeses between an egocentric freeloader and a doggy-like landlord!