Since we don't have much information about this 'cancion pulp fiction', it's difficult to determine the composer. It could be a local artist who created it for a specific event or a niche audience. Maybe it was made by a student of music as an experiment inspired by the 'Pulp Fiction' movie. There are so many possibilities.
I'm not very familiar with this specific 'cancion de pulp fiction'. But if it's related to 'Pulp Fiction', it might have a sense of coolness and edginess, similar to the movie's style.
I'm not entirely sure about the specific origin of 'cancion de pulp fiction'. It could be a song inspired by the movie 'Pulp Fiction'. Maybe it was created by a fan or an artist who was really into the movie's unique style and story. There could be a whole backstory to it that involves the cultural impact of the movie on the music scene.
Yes, the Beastars manga has come to an end. It left fans with a memorable and impactful conclusion that tied up the various storylines and character developments.