Nothing generates suspense in a story quite like a thrilling mystery, and anime has always excelled at generating engagement by keeping secrets from the audience. The more the allure of the enigma permeates the narrative, the less likely fans are to lose interest in it, eager to finally collect all the pieces of the puzzle the anime is building in front of their eyes. Anime classics of the past are defined by their mysteries and their eventual grand solutions, and some long-awaited reveals from iconic series, such as the nature of the One Piece treasure or the conclusion of Guts’ quest for revenge in Berserk, are still awaiting their resolution.
Source:https://www.cbr.com/new-gen-anime-biggest-mysteries/