It's an issue to take up with a lawyer in your country and in the country of origin of the posters tbh. Other people have brought up anime in universe knockoffs but Japan's copyright laws are notoriously more laissez-faire than US or some European countries laws.
It also depends on who owns the properties you're dealing with. Some, like Nintendo, are REALLY UPTIGHT about knockoffs that hurt their brand, coming down hard on counterfeit plushies (low quality) and bowsette (too much nsfw for the children's IP) and famously Pokémon Uranium which was a free game which was in the works for 7 years and taken down 24 hours after launch. Others like most manga publishing houses don't really care as long as you're not undercutting manga sales. You kind of have to be an industry insider to know who's uptight about what though.
I'd say most film houses don't really care about their posters being in an indie comic, but I would advise doing litteraly anything else if you want to one day have a print version of the comic to sell, just to be safe.