A modern classic of dark fantasy and one of the most popular shonen titles of this generation, Tatsuki Fujimoto’s Chainsaw Man is as much a mystery series as it is a thrilling horror action. From the very beginning, Fujimoto enjoyed planting seeds of intrigue into Denji’s story, withholding crucial information from fans and characters alike. A series with so many moving parts and enigmatic puzzles was bound to inspire countless fan theories.
Source：https://www.cbr.com/chainsaw-man-theories-that-make-sense/
