Shintarou Jagasaki, who is a neighborhood police officer, lives with his girlfriend while working a job that is killing him slowly with annoyance. It looks like he will end up marrying soon and live a boring life with a nuclear family - a grim future for a guy with dreams! One such day, a mysterious monster appeared on the train and he suddenly can shoot with his right hand like Master Buppanatsu, the eggplant mascot of his city!
series page (mangahere)
a really interesting experience, four chapters in.
it mostly reminds me of Parasite (which is even mentioned in the story), if it was as violent graphically violent as Gantz.
the story is common 'you have to side with this animala sidekick to fight evil monsters and it ruins your regular life', but has much higher emotional stakes for the main character and his life, and is focused on adults rather than standard highschoolers.
it's just four chapters for now, so give it a try.