The Last Cassette Tape
The very last casette tape of the game can only be found in Hard-mode during last mission "Izban" to the far right of the house. The name of the tape has been blacked out, but because of its contents it seems it was recorded by the Reaper, or maybe even a completely different Reaper.
In the tape, the Reaper describes that every day seems to be the same, he doesn't even know how long he has been in the apartment. After each night of killing Undead, the Reaper just lays on his bed, despite not possessing eyes or eyelids As he doesn't have to eat, drink or sleep he watches the moist grow on the ceiling until the Flame contacts him again.
The most interesting thing is that after the Reaper listens to the tape, a Candle appears in his appartment and takes the cassette, saying "You should not have listened to that" or "That does not belong to you"