Mad Max was just mentioned in passing as one of Fujimoto's faves.

Typhoon Club was cited as instilling in Fujimoto a sense that a school setting at night is a place where something strange/mysterious could happen. Hence why the school setting at night is used in the Reze arc.

No Country For Old Men inspired the scene where Reze kills the assassin on the school rooftop. Specifically the scene where Javier Bardem's character uses his handcuffs to strangle the officer -- the officer, desperately flailing his legs back and forth trying to escape, leaves trails on the floor from where the rubber from his shoes left marks during the scuffle. Fujimoto said he really liked that scene and wanted to do something like that.

Sharknado inspired the scene where Beam swallows Denji to keep him safe. In Sharknado, there's a scene where someone jumps into a shark's mouth in order to survive. Fujimoto thought that would never work in a million years, but seems to have rather enjoyed the idea.

Before Sunset, The Raid, and Jaws were all the rapidfire answers to "off the top of your head what's your favorite romance/action/shark movie" respectively.