Yes, the 'Chainsaw Massacre' was inspired by real - life events. However, it's highly fictionalized. The movie was based on the crimes of serial killer Ed Gein, who had some very disturbing and grotesque behaviors like grave robbing and using human body parts. But the movie added a lot of horror elements and fictional scenarios for the sake of entertainment and creating a terrifying story.
Chainsaw Man follows Denji as he navigates a dangerous world where devils exist. His life changes when he becomes part-devil and has to deal with powerful foes. The story has exciting fights and explores themes like friendship and survival.
There is a Chainsaw Man light novel. It offers new perspectives and adventures within the Chainsaw Man universe. It's worth checking out if you're a fan of the series.